For Jenny Griffiths, eight months in limbo ended with a phone call shortly before midday on 11 March. A body had been found in the woods near the Cribbs Causeway shopping centre, north of Bristol. Personal effects strongly suggested that it was Jenny’s missing great-uncle Derek Serpell-Morris, better known as DJ Derek.

For 50 years, Derek had been a fixture of the Bristol music scene, DJing reggae, ska, rocksteady, dancehall and R&B. Over the past two decades, he had become a national cult figure, playing to packed venues across England and appearing in the video for Dizzee Rascal’s Dirtee Disco. Beyond the novelty value of a white former accountant playing Jamaican music, his love of the music and culture was sincere and profound.

“He was a reggae encyclopedia,” says his friend Don Letts, the film-maker and 6 Music DJ. “He taught me about the importance of culture in bringing people together. He was an English treasure.”

The 73-year-old’s disappearance last July was national news, boosted on social media by Bristolian musicians such as Roni Size and Portishead’s Geoff Barrow. The media covered every development in a search that turned Jenny, who was Derek’s informal personal assistant for a decade, into both family spokeswoman and amateur detective. With that phone call, however, the search was over. The most famous missing person in Britain was no longer missing.

“I prepared myself for the worst, but I stayed strong and didn’t let anything get to me,” Jenny says five days later. “I didn’t cry and I didn’t grieve. So when I had the phone call that confirms your worst nightmare, it was a shock. Maybe I’m still in shock.” Her voice is soft and weary. “I don’t think it’s hit me yet. I haven’t had that crying session yet where you just break down.”

Derek DJing in 2007. Photograph: Jamaway/Alamy

Jenny and her grandmother, Derek’s twin sister Shirley, are sipping tea in Jenny’s living room. The 29-year-old learning support assistant is between jobs, so since last July her sole focus, apart from raising her two children, has been looking for Derek.

“We had concern for Jennifer because she’s been so active,” Shirley says. “This activity can keep you going to a certain extent, but we did try to warn her that after a while, if he hadn’t been found, there had to be a moment when she stops.”

“Which I wouldn’t have done,” Jenny says firmly. “I’d have carried on and carried on.”

While we’re talking, Avon and Somerset police announce that DNA tests have confirmed the body is Derek. Jenny’s phone vibrates constantly with condolences and interview requests.

Derek’s disappearance was unusual. Up to 300,000 people are reported missing in England every year, but the vast majority are found within 48 hours and rarely is a missing person well known. Derek was particularly loved in Bristol. In recent years, he received the Lord Mayor’s medal and a certificate from the people of Bristol declaring him an OBE, or “Outstanding Bristolian Entertainer”. “I remember getting on a bus with Derek once and everyone started clapping,” says Jenny. “That’s how well known he was.”

Before Derek’s disappearance, Letts and Daddy G from Massive Attack were making a documentary that entwined his biography with the story of race relations in Bristol. Daddy G calls him “an ambassador for cultural exchange”. Letts goes further: “He’s a testament to the power of music to change individuals and, in so doing, change the idea of what it means to be British.”

Jennie and Shirley Griffiths. Photograph: Linda Nylind/The Guardian

Derek was born in Bristol in 1941, the second son of a carpenter and a housewife. “He was very introvert,” Shirley remembers. “Nobody ever really knew what he was thinking. If I could have summed him up then, I would have said he was going to be eccentric.”

Derek played washboard in a skiffle group and drummed in a rock’n’roll band before finding a job as an accountant for the Cadbury-owned chocolate company Fry’s. In the early 1960s, he discovered Jamaican music and began attending parties in the St Paul’s district. “I didn’t tell a lot of my white friends,” he wrote in Crossfade, a 2004 essay anthology produced by the Big Chill festival. “It wasn’t worth the hassle. Because all you got was: ‘Oh, it’s rough down there, I wouldn’t go down there.’”

Daddy G had known Derek since he was a child in the 60s. “When my parents first came to England, there wasn’t any infrastructure for the West Indians to integrate with English people, so they used to hold parties themselves,” he says. “Derek was a real novelty to my parents because he was a white guy who had embraced their culture. He was probably the blackest white man that people knew in Bristol.”

In the mid-70s, Derek’s life was upended. Within five years he lost both parents, divorced his first wife and had a brief, volatile second marriage. Oxford DJ Aidan Larkin met Derek regularly and discussed ghostwriting his memoirs, so he knows more about Derek’s past than almost anyone. “The time they [Derek and his second wife] spent together was pretty horrific,” he says. “I think that was the fulcrum of his whole story. I think it’s fair to say in modern terminology that he had a nervous breakdown.”

In 1978, Derek moved into the small basement flat in St Paul’s where he spent the rest of his life, and quit his job. “I didn’t really want to spend the rest of my life totting up figures relating to chocolate bars,” he said in a 1994 BBC documentary. He found DJ work at the Star & Garter, a West Indian pub where customers thanked him for bringing back memories of home, hence his full stage name DJ Derek Sweet Memory Sounds.

BBC documentary DJ Derek’s Sweet Memory Sounds.

“He lost his home, his job, everything,” says Larkin, “and the black community got him back on his feet. He was totally adopted by them.”

“I think he sometimes felt the odd one out,” says Shirley. “And then he found all this love and affection from the black community. Maybe he felt that was more like a family for him.”

The BBC documentary gave Derek nationwide exposure, and by the mid-2000s he was regularly playing such festivals as Glastonbury and Womad, had monthly residencies in London and Oxford, released a compilation album on Trojan Records and toured with reggae legends such as the Wailers. He usually ended his set with One Love by Bob Marley, a song that summed up his belief in bringing people together.

“It’s one of those classic word-of-mouth things. It just grew and grew,” says Big Chill founder Pete Lawrence. “It was great that such an unlikely person could become a superstar within particular communities. He was massively loved by so many people.”

Derek switched from vinyl to MiniDisc (“He backed the wrong horse there,” says Larkin) but still introduced each record in Jamaican patois, which he had learned in a Bristol barber shop. “I found the contrast of this bespectacled old Englishman in his cardigans and fancy waistcoats throwing down some serious Jamaican slanguage quite endearing,” says Letts. “I don’t know anyone who had a problem with it.” Older Jamaican artists loved him. When Derek introduced himself to Toots Hibbert of ska veterans Toots and the Maytals, Hibbert replied: “You don’t have to tell me who you are. You’re the white man who talks the people’s talk and plays the people’s music.”

Derek’s friends became used to his quirks and rituals. They remember him as gentle, good-humoured and scrupulously well-mannered, but prone to complaining loudly when his routine was disrupted. The former accountant remained methodical and frugal in every area of his life. He had a ringbinder full of vinyl catalogue numbers, a cupboard crammed with annotated bus timetables and a giant map of England studded with pins to mark the locations of Wetherspoon pubs. Between gigs, he enjoyed journeying around England on his free bus pass to visit new Wetherspoon branches. “He used to plan his journeys strategically,” says Letts. “It was a military exercise.”

Derek was stubbornly independent. He never remarried or had children, which Shirley suspects may have been his only regret. “He would have been a wonderful father, I think. I don’t really know how he felt. He was a very private man.” His bachelor’s flat was a base rather than a home, with no central heating, hot water, TV or food in the fridge. “I think it was just a place for Derek to sleep,” says Jenny.

Derek at the Larmer Tree festival in 2008. Photograph: Alamy

Derek could usually be found at the Commercial Rooms, a Wetherspoons in central Bristol, drinking pints of Ruddles with the regulars. “He was a lovely bloke,” says his friend Steve Noble. “I didn’t have a bad word for him. He’d get a group of girls coming over: ‘DJ Derek! Can we have a photo?’ He loved that. He’d say to me: ‘Look, ladies’ man tonight.’” He grows quiet. “I’m still looking at the door now, waiting for him to walk through. It’s a big part missing.”

In 2013, Derek decided to retire from regular DJing, telling Jenny that he was tired of the late nights and would only play occasional special shows. The gig he played with Letts in Bristol on New Year’s Eve 2014 turned out to be his last. Jenny later learned that he had opened a savings account for his retirement but, like his pension, it was never touched.

Jenny and Shirley last saw Derek at a family wedding on 13 June last year. When he left, he said he would meet Jenny soon to go through a backlog of Facebook messages and buy a laptop. He had told Letts and Daddy G that he was looking forward to resuming the documentary. “He said he was looking forward to moving forward,” Letts says with a heavy sigh. “He was a trip, man. They ain’t going to make them like that any more.”

The last time Noble drank with Derek at the Commercial Rooms was 10 July 2015. When he didn’t show up on subsequent evenings, Noble initially assumed that Derek, who didn’t own a mobile, was on one of his solitary Wetherspoons jaunts, but after a week he began to worry. Eventually, he reached Jenny through a mutual friend, and Derek was reported missing on 24 July.

“He didn’t want people keeping tabs on him,” Jenny says. “We didn’t live in each other’s pockets. That’s why it took so long to report him missing.”

There were few clues. His bank card hadn’t been used since 6 July and his passport was found in his flat. CCTV footage showed that he had visited the Criterion pub in St Paul’s after leaving the Commercial Rooms on 10 July, while bus company records revealed that he had boarded a number 78 bus to Thornbury, 12 miles north of Bristol, at 10.32 the next morning. After that, his movements were a mystery.

The family considered every possibility: he had killed himself; he had been hit by a car; he had been mugged and fatally injured; he had fallen into a ditch. More optimistically, it was possible that he was lying, unidentified, in a hospital somewhere, or perhaps he had staged a vanishing act. “Maybe he wanted to be known as the legendary Bristol DJ who just disappeared,” Jenny remembers thinking. “Maybe that’s how he wanted to go out.”

A search for Derek in Bristol, July 2015. Photograph: Alamy

Derek’s friends joined searches of the woodland around Thornbury, played fundraisers and kept the story in the public eye. Bar a few cranks and trolls, the public response was overwhelmingly supportive. “All this wonderful coverage and care from people I don’t even know, that’s what you’ve got to hang on to,” says Shirley. “If he hadn’t been famous, there wouldn’t be any of this.”

Jenny explored every avenue, even accepting help from several psychics. “I take it with a pinch of salt, but I wouldn’t leave any stone untouched.” Her own sleuthing was restricted by confidentiality laws. Had she been able to access bus company records herself, she thinks now, they might have helped lead her to Cribbs Causeway. “It’s bloody difficult,” she says angrily. Meanwhile, all leads and possible sightings reported to the police turned out to be red herrings.

“There have been times when I’ve felt like shutting myself away and denying it all,” says Shirley. “I can bear it but I can’t bear too much. The wondering every day if you’re going to hear something: is today going to be the day?”

As time went on, his friends and family began looking for clues as to Derek’s state of mind. Larkin remembers Derek first mentioning retirement when they spoke in January 2013 about summer DJ bookings. “He said: ‘I might not still be here in July. It’s not unknown for people at my time of life to drop dead. And it’s happened to people I know.’ So I think it was on his mind.”

He sold or gave away his vinyl and reacted strangely when Larkin gave him a retirement gift: an album of photographs and gig flyers. “He got a little bit embarrassed and went quiet,” says Larkin. “It was like he was suppressing some kind of emotion.” Before Derek’s body was found, Larkin says: “I’d come to the opinion that he might have taken his own life. Little things he’d said and done had led me to that way of thinking.”

Shirley, meanwhile, couldn’t get out of her head a conversation with Derek at the wedding. He had said that, were his physical or mental health to fail, he didn’t want to be looked after. “So don’t be surprised,” he added cryptically. He hadn’t seen his GP since 2010, but Shirley later learned that he had complained to Noble of a pain in his face the last night they met. “I feel quite strongly that he wasn’t going to say, so he just dropped a few hints about how he was feeling,” she says. “I think he was iller than he was letting on.”

Derek and Jennie. Photograph: Courtesy of Jennifer Griffiths

As summer turned into autumn, hope dwindled, especially when he failed to reappear for a DJ gig for rave collective Arcadia in Queen Square, Bristol. “The moment I gave up hope that Derek was alive was when he didn’t turn up for his Arcadia set,” Jenny says. “He would not have missed that for the world. I knew I was looking for his body, that was my feeling. I wasn’t looking for a live person any more.”

The uncertainty became too painful. On 2 March, Derek’s older brother Gerald, his next of kin, made an application under the 2013 Presumption of Death Act so that his bank accounts, which were still paying his rent and bills, could be closed and a memorial service held. Nine days later, exactly eight months after his final bus journey, Derek’s body was found. “It’s weird,” Jenny says quietly.

The discovery has given Derek’s family partial closure, but it may be impossible to determine the cause of death from a body that has spent eight months in the open air. While we’re talking, the police call to ask to see Shirley and Jenny again. “See how I mean it goes on?” says Shirley, dipping her head. “Why? What? How? When?”

“I feel guilty that I was looking in the wrong places,” says Jenny. “I went to see the spot the other day and I felt physically sick to think that he’d been there on his own for the whole eight months, right by a busy road. I feel sick that it took so bloody long to find him. I don’t feel like I did enough.”

“That’s natural,” Shirley says gently. “You will feel like that, Jenny, but you did more than enough.”

“He didn’t deserve to have a death like that,” says Jenny. “I’d rather he’d had a heart attack while he was DJing because at least then he’d have died doing something he loved.”

She still cannot grieve. She thinks that will only happen when Derek is laid to rest in April. Her memories, at least, are sweet.

“Derek always had a quote: ‘Live the life you love and love the life you live,’” she says with a tired smile. “And that’s exactly what he did. He lived his life and loved it. So I’m at peace with that bit. He’s done amazing.”