Shock twist in mystery of Oklahoma State University students who say they were 'drugged' at their Mexico resort

• READ MORE: Family suggests why their daughters were 'drugged' with fentanyl

Officials in Mexico have claimed the allegations that two college students were drugged with fentanyl-laced drinks at a resort are false.

The head of the State Attorney General's office (FGE), Raciel López Salazar, said an investigation has found that Zara Hull and Kaylie Pitze were never spiked, Riveria Maya News reports.

The Oklahoma State University students were left in wheelchairs after drinking the possibly tainted water on August 2. 

Disturbing images showed them slumped over a poolside bar moments after the alleged poisoning.

But in a statement, Salazar said the girls' drug tests came back clean and that the case has been 'exaggerated and classifies it as simple alcohol consumption'.

'There was no drug dealing here in Quintana Roo with fentanyl,' he added.

Hull and Pitze were on a dream vacation with their boyfriends when the horror unfolded.

It was previously reported they were in Cancun, but in fact they were staying at a hotel in Isla Mujeres, the investigation revealed.

State Secretary of Tourism, Bernardo Cueto, said the students and their families are yet to lodge any formal complaint.

He called the situation a 'very rare case and a very strange situation that is being investigated'.

He told local media his office has approached the United States Consulate to get in touch with the families but is yet to hear back.

'Through the consulate we requested more information from the relatives, but there was no response, there was no interest or intention from the relatives to give us more details of what happened,' Cueto said. 

 'I have to tell you in no uncertain terms it seems very strange to me, a very strange situation because if someone's health is affected in some establishment, the first thing you do is report the establishment where you were possibly or supposedly poisoned.'

Hotels, bars and restaurants have been put on high alert in the meantime. 

Hull previously described the moment she and Pitze passed out in front of her terrified boyfriend Jake. 

'We both got water and within two minutes, Jake had turned around and we both hit the bar, heads down at the same time,' she said. 

Hull said she experienced convulsions before passing out and becoming 'basically paralyzed.' 

Snider rushed her to the hospital and remained by her side as staff reportedly demanded thousands of dollars for treatment.

'They had increased the money they wanted. The baseline was $10,000 for them to even look at me,' Hull said.

'They were holding me captive. We're college students; we don't have the money they're asking for.'

Meanwhile, she suffered from seizures throughout the night, and the doctors intubated her.

Stephanie Snider, the mother of Hull's boyfriend Jake, said she believes they were spiked by people who wanted to harvest their organs or subject them to trafficking. 

'We believe they were planning to take her away to be trafficked or perhaps even to take her organs (which is what we were later told is a common thing that is done),' Snider wrote in an emotional Facebook post. 

Hull claimed hospital staff demanded even more money to release her, and the air ambulance to bring Hull back to the United States cost $26,000.

A day after ingesting the suspicious beverage, the group secured a private plane to fly them to Dallas.

An update on a GoFundMe indicated that Hull is now 'home and well'. 

She initially could not breathe on her own and was put on a ventilator.

Doctors say they have not found anything wrong with Hull, even though she experienced at least 18 convulsions.

Pitze did not end up in the hospital, but had a tough 24 hours after she was possibly drugged.

'Zara is feeling better physically each day-just still a little wobbly and dizzy at times,' Stephanie Snider, Jake's mom said.

'She feels like she needs to sleep a lot but still having a little trouble falling asleep. It seems like when we close our eyes at night many things hit at once of what she’s been through. 

'Kaylie is still struggling with these things as well so prayers are still needed for these girls.

'She will continue working on the physical therapy exercises to get stronger and more stable,' she added of Hull.