“I saw my son fighting for his last breath,” says Anna Nikolin-Caisley. “He went in agony.”

Anna believes her youngest child, Vlad, 17, was “encouraged” to swallow poison by users of an online “pro-suicide” group which is still active in the UK, despite numerous calls to ban it.

Vlad’s family have decided to reveal the harrowing details of his death, in Hampshire in May 2024, as a warning to others.

The government said platforms must remove illegal suicide and self-harm content when new rules come into effect this year as part of the Online Safety Act.

But the Samaritans charity says it does not believe the new law goes far enough.

Warning: The following article contains upsetting content

It was 02:40 on 7 May when Anna was jolted from her sleep by her teenage son Vlad screaming, “Mum! Call doctors!”

He then shouted the name of a poison and the time he drank it.

“I don’t know what the substance is,” Anna remembers, “but he’s changed his mind, and he came to me for help, to save him.”

Vlad’s father, Graham Caisley, describes how their son must have staggered upstairs, before collapsing on his bedroom floor.

“His hands were all clenched up and he was shaking,” Graham says. “It was just a state of panic.”

“It was violent, it was sudden,” his mother adds, as she describes her son suffering multiple seizures. “Fitting and fighting for life – I can’t even start imagining the terror he went through.”

Minutes later, Graham was on his knees carrying out CPR on his son, guided by paramedics on speakerphone.

“I was just doing what I could to try and save my son’s life,” Graham says, with tears in his eyes. “It was just horrible.”

Police body-worn camera footage reveals the chaos and emotional fallout as emergency responders tried and failed to save Vlad’s life.

After Vlad’s death his family were shocked to discover he had been sharing his “dark moments” with people online. His mother says it was a “very secretive” community and describes it as a “pro-suicide” cult.

Detectives found a “suicide kit” in the family’s Southampton home, containing various poisons, pills and other things Vlad had bought after joining the chat group.

“He’s researched and understood, and been told where to buy these things and what to buy,” says DS Chris Barrow from Hampshire Police. “So, without the website, Vlad wouldn’t have been able to put together this set of items and ingredients with which to take his own life.”

After a happy childhood, Vlad had begun to withdraw in his early teens and was later diagnosed with autism, depression and anxiety. At the time of his death he was being treated by mental health professionals and had also developed a painful neurological condition.

His family say they had seen his mental health improve as he had started seeing friends and travelling. But Vlad’s older sisters, Masha and Mia, say even though he was much better, he was still vulnerable when he took his own life.

“Even if people using this forum struggle,” says Masha, “no-one knew my brother well enough to make any decisions about his life.”

Mia, who has exchanged messages with moderators on the website, describes the site as an “echo chamber” which can “push people over the edge”.

“There is almost definite grooming taking place,” she says.

The BBC has spent years investigating the online forum that Vlad was a member of. It now has more than 50,000 members globally and Vlad’s family want it taken down or blocked.

By coincidence, Vlad had ordered poison from a Ukrainian seller called Leonid Zakutenko, just before the BBC exposed him.

But Vlad did not swallow that poison. The chemical he eventually ingested was ordered from Poland and had been mis-labelled, possibly to get through customs.

Following his death, the family read all Vlad’s posts and exchanges on the forum and describe how things appear to have “slowly escalated”.

Vlad’s mother, Anna, says: “Then you have private chats and you are led down the path of death. Anyone can come across it. A child can come across it. There’s no checks.

“The people who sold the poison, the people who encouraged it, how is that legal?”

“They’re alive,” Vlad’s father, Graham, says, “our son is dead.”

The police investigation into Vlad’s death, to establish if any criminal offences have been committed, is ongoing.

The website is based in South America and hosted by a server in the United States. With different laws in different countries, online harm is notoriously difficult to police.

Data from the Office of National Statistics shows suicides in England and Wales have risen by 10% over the last six years. Although it is still rare for under 25s to kill themselves by poisoning, the numbers of young people choosing to end their lives in this way are rising more quickly than in older people.

A government spokesperson said, “Suicide devastates families. Intentionally encouraging suicide or the serious self-harm of another person is illegal.

“Once the Online Safety Act is fully implemented, platforms will have to remove this illegal suicide and self-harm content as well as stop children from seeing harmful suicide related material – even when it falls below the criminal threshold.

“Companies should not wait for laws to come into force – they must take effective action to protect all users now.”

Julie Bentley, CEO of Samaritans, says the charity’s calls for smaller sites to be treated as severely as larger platforms have been “completely ignored”.

“Legal-but-harmful content needs to be strictly regulated for both adults and children,” she says, urging both the government and Ofcom to act “before it’s too late”.

Ofcom told the BBC that from July sites would have “duties to protect children from harmful self-harm and suicide content, even where it’s not illegal”.

“As these duties come into force, we’ll be able to use the full extent of our enforcement powers against any services that fail to comply with their duties,” it added.

Additional reporting by Jonathan Fagg, Senior Data Journalist