A first-year student took his own life using poison he bought online and had delivered to his university halls from a Canadian who pretended to be a doctor, an inquest heard.

Joshua Warner, 21, had decided to end his life a month before he died on January 31, 2023, and researched poison before buying it from Kenneth Law, an online dealer who supplied substances linked to 79 deaths in the UK.

The psychology student suffered from borderline personality disorder, ADHD and depression, with a coroner ruling that doctors ‘could not have prevented’ his suicide.

Mr Warner bought the poison from Law, then 57, through a chat forum. It was delivered to Rosalind Franklin Halls, Portsmouth, before he died by suicide in the early hours of the morning.

Law, now 60, pleaded guilty to aiding and abetting suicide om Canada after he pretended to be a doctor - though actually a chef - and sold poison to the student for C$81.72 (£45).

He will have Mr Warner’s name added to his criminal case after the National Crime Agency (NCA) linked the student’s death to Law, of Mississauga, Canada.

Anna Smith, a senior investigative officer at the NCA, said the agency had tracked Law through a company and website linked to him through Mr Warner’s payment for the poison.

Ms Smith added that Law supplied 330 products to the UK from Canada, which were linked to his PayPal account and ‘directly’ led to 79 deaths.

Law is due to be sentenced next month and Ms Smith said Mr Warner’s name would be included in the case against him.

Mental health professionals who treated Mr Warner said he had told them he was starting to feel better and his newly-prescribed medication was working days before his death.

In a written statement Mr Warner’s father, Dr Graham Warner, said his son was ‘a great food critic’ and ‘made a brilliant seafood paella’.

‘He loved Nandos, Taco Bell and Dungeons and Dragons,’ Dr Warner added.

“At Woking High School, he made his friend group. He committed to study Psychology in Portsmouth. He was a brilliant wordsmith.

“He was too clever, too thoughtful, too trapped in his own thoughts. Josh was loved, so deeply loved. We are so deeply sad but we are proud of him.”

Stephanie Warlow, Mr Warner’s mother, said her son was ‘always a very closed book, a very private person’.

‘I was not really aware that he had such bad mental health problems,’ she said.

Concluding the inquest Nicholas Walker, the area coroner for Hampshire, Portsmouth and Southampton, said: “Joshua was, and is, so much more than the conversations we have been having. Unique, quirky, fiercely loyal, a dry sense of humour and quick wit.

“His family describes him as being a deep thinker, and introspective.

“Sadly, you say, he was too trapped in his own thoughts. He was able to deceive people of those inner thoughts that were eroding his mental health. I am satisfied that he intended to take his own life.

“It seems to me that the heart of this case is whether the professionals should have seen through Joshua’s deception - he was apparently getting better.

“I am satisfied, on the balance of evidence, that Joshua’s death could not have been predicted or prevented. He was saying that he was feeling better; he was an intelligent young man, and even those who knew him best did not see his coming.”

Mr Walker said Mr Warner’s family were left ‘frustrated’ by medics as they tried to help him access treatment.

Only through Dr Warner’s ‘dogged perseverance’ - he emailed the chief medical officer of what was Solent NHS Trust over Christmas 2022 - was his son finally assessed by doctors a month before his death.

Mr Walker said: “It should not be down to the dogged perseverance of a concerned father to get the help that was needed.

“I’m quite satisfied that he would not have had a consultation, had it not been for his dad. It should not have taken that.”

Mr Warner’s cause of death was recorded as intoxication from a highly toxic substance and Mr Walker recorded a conclusion of suicide, saying the student, also known as Jeremy, intended to take his own life.

The substance which caused Mr Warner’s death was named in court but has been excluded from reports in line with guidance on reporting suicide and the coroner’s recommendation.

Though the substance is available in the UK, the court heard it is not sold to individuals.

Mr Warner’s GP surgery, NHS trusts and the University of Portsmouth had all found ‘areas of learning’ after his death, though not all were directly linked to his suicide, the court heard.