A mum who admitted to ending the life of her terminally ill son by giving him a deadly dose of morphine has died.

Antonya Cooper, 77, from Abingdon, Oxfordshire, died over the weekend after being diagnosed with terminal breast, pancreatic and liver cancer, her family said in a statement. Cooper recently admitted to having ended her seven-year-old Hamish's life in 1981 in an effort to change the law around assisted dying.

Following Cooper's admission, police said they were investigating the case. Assisted dying is not legal in the UK.

Thames Valley Police are understood to have visited the family following a BBC report on Wednesday. In the interview, Cooper admitted to having ended her son's life.

Hamish suffered from neuroblastoma, a rare cancer (
Image:
PA)

"She was peaceful, pain-free, at home and surrounded by her loving family," Cooper's daughter Tabitha said in a statement sent to the BBC. "It was exactly the way she wanted it. She lived life on her terms and she died on her terms."

Hamish, seven, suffered from neuroblastoma, a rare cancer that affects children. While it mostly affects children under the age of 5, around 100 children between 0 and 14 are diagnosed with it in the UK every year.

Cooper said Hamish had been in a lot of pain and following 16 months of treatment, she admitted to having given him a large morphine dose through his Hickman Catheter. She claimed it "did quietly end his life."

Cooper died over the weekend, according to her family (
Image:
PA)

When asked whether she understood police would potentially open an investigation into manslaughter or murder, she responded: "Yes." Cooper added: "If [the police] come 43 years after I have allowed Hamish to die peacefully, then I would have to face the consequences. But they would have to be quick because I'm dying too."

Cooper further explained the reasons behind her decision: "I feel very strongly that at the point of Hamish telling me he was in pain, and asking me if I could remove his pain, he knew, he knew somewhere what was going to happen.

"But I cannot obviously tell you why or how, but I was his mother, he loved his mother, and I totally loved him, and I was not going to let him suffer, and I feel he really knew where he was going."

Thames Valley Police previously said it was “aware of reports relating to an apparent case of assisted dying of a seven-year-old boy in 1981”.

'Right to die' campaigners argue people should have a right to choose when and how they die in order to avoid suffering. Critics argue changing the law would "place pressure on vulnerable people to end their lives."