In Cheam, Sutton – a large suburban village that starts where Greater London and Surrey intersect – there's a church named after Saint Dunstan.

The modern St Dunstan's Church was built in 1864, but the site has had a place of worship sitting on it since Anglo-Saxon times. In 2011, the church made national headlines for being the site of a youth club named The Shed. It was here in the late-1980s that the church's groundkeeper and the club's founder, former soldier William Lambert, abused children in a dilapidated hut in the church's grounds. The hut isn't there now; it's long burned down. Painful memories, however, live on.

Lambert claimed he was a warlock who could pass on his powers to the children he abused through sex. During a 2011 trial, a court heard that Lambert raped a child on a tombstone, claiming she would get power from "the black floating monk" who he told her haunted the church. Another time, a girl confided in him her fears she was pregnant. He coerced her into having sex with him by claiming that if she did, she no longer would be. His victims were aged between 11 and 15 years old. In May of 2011, aged 75, Lambert was jailed for 11 years.

Dunstan, the Anglo-Saxon saint the church is named after, is renowned for his battles with the devil. Born in Somerset in the year 910, religious scripture tells us that, in later life, Dunstan was approached by the devil with a view to recruiting him to his cause. Dunstan chased him away with tongs. In the real world, however, this Grade II listed building continues to be soiled by the wrongdoings of the past. In recent years, St Dunstan's graveyard has been excavated twice. First in 2012, between June and September. Then again in the April of the subsequent year. It's believed that its graveyard is the final – unmarked – resting place of the missing schoolboy Lee Boxell.

Lee Boxell

"Lee was our first child," says his father, Peter, today. "His birth was a dream come true for me. I couldn't wait to get home from work to spend time with him. He was a really good kid. Average at school, but with some really good friends. He was interested in a girl who lived nearby and would often take a neighbour's dog for a walk as an excuse to meet her. He loved music. I took him to see Shakin' Stevens in concert once, which he absolutely loved. He was always phoning the radio stations to enter competitions about pop music. Taping songs he liked off the radio. He was quiet. Well behaved. Considerate. Sensitive. Possibly too trusting and not streetwise. I miss him."

When Lee Boxell vanished, almost 31 years ago, he was 15 years old. The last confirmed sighting of him was on the day he went missing, Saturday the 10th of September, 1988.

"It was a warm, sunny day," says Peter. "My wife Christine was going to visit Lee's grandmother. His sister was going to see a friend and I was going shopping. I remember him coming down from his bedroom in the morning, still in his pyjamas, and sitting in an armchair. I asked him what he planned for the day. Half-asleep, he mumbled something, but I could see that he wasn’t fully awake, so I decided not to ask him again. We all left the house. That was the last time I saw I ever saw my son."

We know that after his family left that day, Lee put on his black jeans, his brown suede shoes, his Swatch and a white T-shirt with an image of The Flintstones printed on the front. He headed off to Sutton to meet his friend, Russell. The two boys mooched around for a bit, parting company at 1PM. Lee, a big football fan, said he might go to Crystal Palace's Selhurst Park stadium to watch a game. His team, Sutton United, were away in Lancashire. Lee would watch football wherever and whenever. "He was Sutton United mad, was Lee," says Peter, "and he often went to away games on the supporters' bus – but he wouldn’t have gone that far, and not that last minute."

This was the era in which Charlton Athletic shared a ground with Palace. The fixture Lee had his eye on was Charlton vs Millwall. Following extensive reviews of crowd footage after that fixture, it's believed that Lee never made it to the match. For one thing, there's a supposed sighting of him outside a Tesco (now an ASDA) on Sutton High Street at 2.30PM. He couldn't have made it to Selhurst Park for kick-off.

The Boxells sensed something might be wrong at around 5PM – during this era, the time that the day's football calendar drew to a close. If he didn’t come straight home afterwards, Lee would always call at full-time to say when he'd be back. "He always did that," says Peter. "He'd always find a payphone, even though so many were vandalised."

"Lee's mum called me in the evening and panicked when I told her that Lee hadn't come home," continues Peter. "She got a cab back to our house. We contacted Lee’s friends, neighbours and relatives. We called local hospitals in case Lee had been admitted after an accident. No one knew where Lee was. I knew that Anthony, one of Lee’s close friends, had gone to the coast with his parents. They lived nearby, so I awaited their return home thinking Lee might have gone with them. Anthony arrived late that night, but without Lee. I then contacted the police. They said Lee would probably turn up."

Lee didn't turn up. As hours became days, days became weeks, weeks became years – despite Crimewatch specials, TV appeals by the Wimbledon footballer John Fashanu and the T'Pau singer Carol Decker, Lee's face being printed on milk cartons, and even his inclusion in the video for the missing-kid-anthem "Runaway Train" by the US indie rock band Soul Asylum – the family still waited.

Lee Boxell with his family before he disappeared.

Until 2013 – the year that Lee would have turned 40 – when a tip-off in the wake of the Lambert investigation prompted police to believe that Lee might be buried in the graveyard of St Dunstan's, just a mile away from the Boxell's family home. The idea that Lee had attended The Shed, witnessed abuse, tried to stop it and was then killed was floated. Witnesses said they'd seen him at the club from time to time. "I do think that if Lee had gone to The Shed and seen another child being assaulted, it would have been in his character to come to the victim’s aid," says Peter.

Scotland Yard's biggest ever archaeological dig followed. Ground penetrating radar used by the army was deployed. They found nothing. Hope that answers might arise for the Boxells then came when three men – aged 78, 42 and 41 – were arrested on suspicion of murder, conspiracy to pervert the course of justice and indecency with children. A 42-year-old woman was also arrested on conspiracy to pervert the course of justice and indecency with children. However, all were released without charge.

"There have been rumours Lee is still alive," says Peter. "I'd love that to be true, but it’s highly unlikely. The only sightings of Lee in recent years are by persons who are associated with the suspected murderer, so are highly suspect. If Lee is alive, others would have seen him…"