I feared my vulnerable son, 35, had been taken advantage of before he died in a random flat in Preston

Matthew Nickolson, 35, of Preston, was described as a ‘naive user’ of heroin who hadn’t been taking the drug very long and didn’t use it very often.

On the night in question, he had taken the two drugs together, a practice called speedballing which increases the ‘high’ effect while taking drugs.

But Dr Stephanie Martin, Consultant Clinical Scientist and Toxicology Lead, said that although the cocaine counteracted the effects of the heroin, once the cocaine had quickly worn off, the full sedative impact of the heroin took effect.

Matthew died in Preston on November 17, 2023, as a result of heroin toxicity.

Lancaster Coroner, Dr James Adeley, who is Lancashire’s senior coroner, recorded a drug-related death.

The behind the scene story of Dr Adeley’s quest to uncover the truth behind this tragedy was featured in the latest episode of the award-winning documentary, Cause of Death.

Join our new WhatsApp Community to get the latest news and top stories from across Lancashire directly to your phone. This Chennel 5 series follows the start of each case and tracks Dr Adeley's efforts, working in tandem with Lancashire Police and the county’s hospitals, to find out what led to the unexpected death in each case.

The story of Matthew’s death was particularly heart-rending and poignant.

When he was found on the sofa in the Preston flat, the occupant knew him only as ‘Matty’ and did not know his surname or where he lived - and Matthew had no ID on him.

This meant that both the police and the coroner had to begin a search to find out who ‘Matthew Unnown’ really was.

After they placed an appeal on Facebook, police were contacted by Matthew’s worried stepfather, who said his stepson was called Matthew and had gone off the radar.

It was then that Matthew Nickolson was identified.

His heartbroken mum, Karen Nickolson, of Inskip said: “Matthew was vulnerable and trusting he had learning difficulties, development delay, dyspraxia, dyslexia and autism, but he was a good boy.

“He would do anything for anybody.

“He always said to me ‘mum, let me live my life, I’m an adult’ but he wouldn't think about the consequences. He wasn't an adult in the way other people were.”

His supportive parents arranged for him to get his own flat and he did well at first, but they discovered that other people were staying there, even when Matthew wasn't present, and it appeared he was being taken advantage of,

Despite the efforts of his mum and stepdad, he ended up homeless and fell into the sporadic drug use that would cost him his life.

Dr Adeley summed up at the end of the programme: “Familes in cases such as these often ask themselves, ‘could I have done more’ but the difficulty is you’re dealing with adults who make their own choices.

“It;s very difficult to stop these things from happening.”

Cause Of Death airs on Wednesday nights at 9pm on Channel 5. You can also stream it onMy5 here.