“It’s awful. You never forget how much it hurts.”

Ham & High: King's Cross station front. Picture: Polly HancockKing's Cross station front. Picture: Polly Hancock (Image: Archant)

Later this month, more than 1,000 leaflets will be handed out in King’s Cross and Camden to passers by and members of the homeless community in an attempt to find a 37-year-old who went missing 20 years ago.

Paul Watson, who grew up in Chislehurst, is thought to have connections to the area. His parents lost contact with him as a 16-year-old, during a half term in 1997, and he hasn’t returned home since.

His mother, Pauline Davis, said: “We didn’t realise he had gone initially. He was living with me and his step-dad Graham in Brighton and said he was going to visit his dad in Chislehurst. He said: ‘I’ll be back with a card and presents for Mother’s Day.’”

Paul’s father initially knew he was spending time with friends nearby, but over time lost track of him and he never returned to the south coast. Pauline moved there 32 years ago, after separating from Paul’s father, then met Graham.

After his disappearance, Pauline and Graham heard he was in Hackney. They visited the area and spent a day walking the streets looking for him.

“We were so green, we didn’t realise what Hackney was like,” she said. “We spoke to some police who said: ‘You shouldn’t really be around here.’ We didn’t realise how dangerous it was.”

A conversation with a homeless man who said he knew of Paul proved fruitless and they returned to Sussex without success.

Several months later, in 1999, his mother had a phone call out-of-the-blue from a solicitor saying Paul had been arrested and was in prison in Pentonville for possession of heroin.

He had been spending time on the streets and had become mixed up in Camden’s drugs community.

Pauline and Graham visited him in prison and were hopeful he’d return home with them when he was released a month later.

“It was an eye-opener,” she said. “I’d never visited before and they take everything off you. They even took Graham’s bus ticket off him before we went in.”

After initial concern when Paul was last to emerge, they both offered him help and support. There was even a moment of humour when his mother joked that expensive dental work done when he was a child had been ruined by his drug usage.

“It was the same Paul we’d known,” she said. “His hair was long, and he still had his young face. We had spoken to support services, and Graham had spoken to his doctor and dentist about being able to help Paul. We said we would help when he came out.”

The night before he was released, he phoned Pauline to say he would be released at midday. But to her and Graham’s horror after waiting outside the prison during a cold February afternoon, they found he had been released two hours earlier than planned and had disappeared.

Growing up in leafy Chislehurst, Paul was known as an outgoing boy with a large group of friends. He was a big cinema lover, good at drawing, and sang in a choir.

“We think about him every day,” said Pauline. “Graham and I go to the cinema, and think: ‘Paul would have liked this,’ or go on holiday and think: ‘Paul would have enjoyed this.’

“Every morning I wake up, and I’ve got a picture in my kitchen. I kiss it, and say: ‘Good morning, Paul. I hope you’re warm, and I hope you’re safe, and have something to eat.’

“I’ve always got him in my mind, but you can’t let it rise to the top, otherwise you would never cope.”

Pauline has never changed her phone number, because she believes it’s one Paul remembers and would use to get in touch.

The last contact his family had with him was a series of fines from British Transport Police relating to King’s Cross and Gower Street, which were sent to her address about a decade ago.

“It was so hard,” said Pauline. “I didn’t pay them, because I didn’t want it to keep happening, but I feel so upset because it feels like I’d not helped him.”

Paul’s parents have asked Brad Fox, from Fox Investigation Services in Kent, to lead the search. Brad has managed to find records of him being admitted to UCL Hospital in 2012. He is still believed to be alive, as police have his DNA from his spell in prison two decades ago and it hasn’t been matched with any bodies found by the Met.

Brad and his team will be distributing leaflets in King’s Cross and Camden on February 27.

His mother’s heartfelt message is clear: “Get in touch. We are still here and love you, and want to help. What’s happened has happened. Even if you don’t want to see us, just get in contact.”

Call Brad Fox on 07506 391313 or email info@foxinvestigation.net if you have any information.