EXCLUSIVEJay Slater: The county lines connection. FRED KELLY reveals the growing links between missing teen's final hours and the criminal underworld. Read his exclusive investigation

As night falls, the Papagayo Beach Club descends into a cauldron of noise and narcotics. This is the jewel in the somewhat sordid crown of Veronicas Strip, a collection of neon-lit bars adjacent to the resort of Playa de las Americas in Tenerife.

Every night this week — in what we might call the post A-level party season — hundreds of British teenagers filled its chaotic dancefloor, on what for many was their first holiday without their families.

When the Mail visited Papagayo, the self-proclaimed 'Icon of the Canary Islands' was full to bursting. But as the ear-shattering dance music blared, no one seemed to care or even remember that less than three weeks ago, the missing teenager Jay Slater had been doing exactly the same thing.

For it was here that the 19-year-old trainee bricklayer from Oswaldtwistle, in Lancashire, spent the final night before his bizarre disappearance. Images from the early hours of Monday, June 17, show Jay bare-chested on the club's dancefloor.

Like many revellers, his mouth was open and jaw locked to one side, an expression consistent with ecstasy or ketamine abuse. It was the final hours of the three-day New Rave Generation music festival which he and three friends had flown out to attend.

Jay Slater, a 19-year-old trainee bricklayer from Oswaldtwistle in Lancashire, went missing in Tenerife last month

Jay Slater, a 19-year-old trainee bricklayer from Oswaldtwistle in Lancashire, went missing in Tenerife last month

Ayub Qassim, 31, has been identified as one of the two men who drove Jay to an Airbnb in Tenerife

Ayub Qassim, 31, has been identified as one of the two men who drove Jay to an Airbnb in Tenerife

But, as we know, Jay's night did not end well.

Having allegedly stolen a £12,000 Rolex watch from an unnamed eastern European man outside the club (later allegedly sending a Snapchat message to friends saying he intended to sell it), Jay made what increasingly looks like an ill-fated getaway in the rental car of two mysterious men who drove the teenager to their Airbnb, 25 miles north, near the hilltop village of Masca.

And, as is becoming alarmingly clear, these weren't just any men. As the Mail revealed this week, one of the pair has been identified as Ayub Qassim, who was jailed over nine years ago for being the architect of a sophisticated and extensive Class A drug dealing operation across Wales.

When approached by the Mail, Qassim, 31, — who booked the Airbnb under another name — simply said: 'The only comment I have to make is that Jay came to the house alive and he left the house alive.'

Unfortunately, as the true extent of Qassim's murky past emerges, this short riposte is proving hopelessly insufficient.

Now, it has been revealed that he is a close friend of the drill rapper Potter Payper, 33, whose real name is Jamel Bousbaa.

Video footage from this year's Mobo urban music awards held in Sheffield shows Qassim standing beside the prize-winning rapper wearing a garish, diamond-encrusted necklace. Qassim also makes a cameo in one of the rapper's music videos.

And it turns out that Bousbaa also has form when it comes to drugs. He was sentenced to more than five years in prison for running his own Class A narcotics operation in Barking, East London, which used a 'county lines' network of young people to deal drugs in provincial towns.

He was released in 2020 and now owns a marijuana store in Tenerife called Potter's Garden, which sells multiple strains of cannabis, including one notorious plant known only as Potters Z. (Possession of marijuana for personal use is not a criminal offence in Tenerife.)

Bousbaa's soft-spot for high-strength cannabis is evident in his rap lyrics. One of his most popular tracks, Thanks For Waiting, opens with the line: 'Nowadays when I speak, it's a big saga. Nowadays I collab with the weed farmer.' The song also includes the line: 'I don't smoke paigans, I smoke ganja spliffs.'

Qassim is a close friend of the drill rapper Potter Payper, 33. Footage from this year¿s Mobo urban music awards shows Qassim standing beside the prize-winning rapper wearing a garish, diamond-encrusted necklace (left)

Qassim is a close friend of the drill rapper Potter Payper, 33. Footage from this year's Mobo urban music awards shows Qassim standing beside the prize-winning rapper wearing a garish, diamond-encrusted necklace (left)

Qassim was jailed over nine years ago for being the architect of a sophisticated and extensive Class A drug dealing operation across Wales

Qassim was jailed over nine years ago for being the architect of a sophisticated and extensive Class A drug dealing operation across Wales

What's more, Bousbaa is a known associate and friend of another, more famous, UK rapper, Big Narstie, who once had his own show on Channel 4 and also owns Tenerife's biggest and most notorious marijuana coffee shop, BDL. The New Rave Generation festival held an event there the afternoon before Jay went missing.

In other words, Jay Slater was not driven away from Papagayo by any normal fellow reveller but by a convicted drug dealer with extensive and ongoing connections to the narcotics trade in both the UK and Tenerife.

With this in mind, it seems astonishing that police allowed Qassim and his companion that night — known only as 'Johnny Vegas' — to return to the UK.

The duo were questioned but almost immediately released by Spanish detectives investigating Jay's disappearance, with the police chief in charge of the operation claiming at the weekend that the pair were 'not in any way relevant to the case'.

That seems questionable, even by the standards of Tenerife's authorities, who have a remarkably relaxed attitude to their island's drug culture.

Meanwhile, they are no closer to solving the mystery of Jay's disappearance.

As we know, at around 5am on Monday, June 17 — having left Papagayo in a Seat Leon hire car — Jay, Qassim and the third man arrived at the £40-a-night Casa Abuela Tina rental property. At roughly 7.30am, Jay posted two images of himself on Snapchat, signalling he was safe and well.

Thirty minutes after that, he was spotted at a nearby bus stop by Ofelia Medina Hernandez, whose brother owns the Casa Abuela Tina Airbnb. Ofelia told Jay the bus wasn't due until 10am but, rather than returning to the property, he made the inexplicable decision to attempt to walk the 25 miles south to his own lodgings.

This begs some questions: had a weekend-long binge left him tired, confused and behaving irrationally? Or did he fear for his safety at the Airbnb? Was he trying to escape from Qassim, his associate, or someone else?

Whatever the answer, Jay took the road north in the opposite direction to where his holiday apartment was situated, apparently on the basis that it was the route recommended by the Apple Maps app on his phone, according to Mark Williams- Thomas, the former police officer who is unofficially investigating Jay's disappearance.

Jay Slater pictured with his mother Debbie Duncan. The teenager has been missing since June 17

Jay Slater pictured with his mother Debbie Duncan. The teenager has been missing since June 17

Jay was seen dancing in a Playa de las Americas club with friend Lucy before he disappeared

Jay was seen dancing in a Playa de las Americas club with friend Lucy before he disappeared

Jay travelled to the Casa Abuela Tina Airbnb (pictured) in the village of Masca with two older British men before he went missing

Jay travelled to the Casa Abuela Tina Airbnb (pictured) in the village of Masca with two older British men before he went missing 

At 8.30am, he called Bradley Hargreaves, a friend who had travelled with him to Tenerife, via Snapchat, saying that he'd left the road and was walking cross country.

Twenty minutes later — showing the first signs of distress — he rang a second holiday companion, Lucy Mae Law, to reveal he was 'lost in the mountains, with no water and 1 per cent battery'. Jay's phone then 'pings' at 8.51am in a ravine within the Rural de Teno Park, a few miles north of Masca, which is his last-known location.

On Thursday morning, the Mail visited the deep and treacherous ravine, where rescuers had conducted an ultimately fruitless 12-day search before calling off their efforts last Sunday.

The terrain is unforgiving. Sharp-needled cacti grow higher than a man's head and there's no sound other than the noise of geckos scuttling in the undergrowth and the distant howl of the wind above the ravine.

Alone, in the morning heat, one false step could easily have led to a fall and near-certain death.

In a sinister twist, the Mail found eerie signs of life in one of two ruined homesteads in the ravine: shoelaces tied with twigs to form haunting symbols like something out of a horror film, empty water bottles, and — most strange of all — a set of clean women's clothes.

Climbing out of the ravine and looking back down at the dense shrubbery, it is easy to see how a body could go undiscovered. One woman who bravely refuses to give up hope of finding Jay is his devoted mother, Debbie Duncan.

Along with his father, Warren, and brother, Zak, she has been staying at the Club Tenerife hotel in Los Cristianos, desperately hoping for good news, or — at the very least — closure.

Qassim rented the Airbnb which missing raver Jay visited just before he disappeared

Qassim rented the Airbnb which missing raver Jay visited just before he disappeared 

Volunteers gathering ahead of a final 'massive search' for Jay Slater, which was called off by Spanish police the following day

Volunteers gathering ahead of a final 'massive search' for Jay Slater, which was called off by Spanish police the following day 

'We are a very close family and are absolutely devastated about his disappearance,' Debbie said in a statement on Tuesday. 'Words cannot describe the pain and agony we are experiencing.

'He is our beautiful boy with his whole life ahead of him and we just want to find him.'

Yet the Jay Slater case has certainly done little to dampen the enthusiasm of revellers on this party island.

Kevin Molloy, a 22-year-old from Ireland, is on a nine-week holiday in Tenerife with his girlfriend, as they both enjoy a long summer away from college.

Jay disappeared three weeks into their trip, but Kevin barely registered it. 'A bartender mentioned it to me,' he says. 'But otherwise, I haven't seen any posters or anything. Just what I've read online.'

Indeed, the internet has become a cesspit of conspiracy theories propagated by amateur sleuths. 'It's impossible to know what to believe,' admits Kevin, who is clearly unconcerned.

But others are taking Jay's disappearance more seriously. Two 20-year-old holidaymakers called Harry and Ed are enjoying a week away. 'We're certainly more wary now,' says Harry. 'Our families warned us to be careful and we won't be going to Veronicas.'

Just minutes before talking with the Mail, the pair had been approached near the strip — in the middle of the day — and offered 'charlie': 'Which I think means cocaine,' Harry added, tentatively.

I had a similar experience while walking down Veronicas in the early afternoon. A group of North African men purporting to sell knock-off designer sunglasses approached me.

'What are you really selling?' I asked them.

A grin came across the face of one of the street-hawkers. 'Cocaine, marijuana, come with me, my friend.' It was as simple as that.

The latest revelations about the drug links of Jay's last known associate Ayub Qassim only deepen suspicions that his disappearance is in some way linked to the island's thriving narcotics trade. It's an association that has begun to tarnish the name of Jay Slater, who has a previous conviction for assault. 

'There's more to this than meets the eye,' a man in his 50s told the Mail, his belly bulging over Wolverhampton Wanderers football shorts. 'I've read about Jay Slater's past. He isn't your average young man. Something doesn't add up.'

Indeed, the longer this unsolved case rolls on, the more suspicions seem to arise.

Jay Slater is not the only British citizen to go missing on Tenerife. Kevin Ainley, 24, also from Lancashire, was working as a promoter for a bar when he disappeared just over two decades ago. He remains missing to this day.

And in 2019, 34-year-old father-of-two Peter Wilson went missing after a night out. His body was found two years later at the bottom of a sheer drop beside a shopping mall. Both of these disappearances represent tragedies for their families.

It must not be forgotten that at the heart of Jay's story is a mother who is desperately clinging on to the hope that her son is still alive.

But, sadly, as the days go by here in Tenerife, Debbie Duncan's desperate calls for help are becoming ever fainter, drowned out by the thudding dance music that pervades this notorious party island.

Additional reporting: Nick Pisa