A man has appeared in court accused of murdering two girls in Brighton in 1986.

Russell Bishop, 51, appeared by video link at the Old Bailey and was charged with the murders of nine-year-olds Nicola Fellows and Karen Hadaway.

The deaths of the Sussex schoolgirls have remained one of England’s most notorious unsolved murder cases for more than 30 years.

Bishop, formerly of Hollingdean, Brighton, pleaded not guilty and was remanded into custody. He will stand trial in September in a trial expected to last eight weeks.

Facebook Twitter Pinterest A court artist’s sketch of Russell Bishop, who appeared via video link for a plea hearing at the Old Bailey. Photograph: Elizabeth Cook/PA

The bodies of Nicola and Karen were discovered in bushes in Wild Park, Brighton, a day after they vanished on 9 October 1986. More than 150 uniformed police, 30 detectives, relatives and friends joined the search for the girls. They had been taken from close to where they lived, on the Moulsecoomb estate in Brighton.

In a statement marking the 30th anniversary of their deaths, Nicola’s uncle, Ian Heffron, said the families would “never give up in our hope for justice and closure”. Speaking in 2016, Heffron said: “We live for the day we can truly see them rest in peace.”

In an interview with the Guardian 16 years after the girls were killed, Karen’s mother, Michelle, said she had lived with terrible guilt that she could have saved her daughter.

“She was only out for 20 minutes because we were going to my friend’s house that night. She said, ‘I’m just going out to play’. Initially, I thought that maybe she was in somebody’s house playing and she’d lost track of time. I never thought for one minute that they weren’t coming back.”

Karen’s father suffered a fatal heart attack in 1998, brought on, his family believes, by the stress of losing his daughter.

Nicola’s mother, Susan Fellows, who remarried, spoke about how her daughter’s death had affected her. “I’ve got a big photograph of Nicky in a frame on the living-room wall, and I talk to her all the time: what would she be doing now? Would she be married, would she have children?

“I wouldn’t want anyone to go through what we’ve been through. You have to live with the memory of that night, when you walked the streets, thinking what you were going to do when you got hold of her for coming in so late.”