The man known as “Nick” whose claims of a VIP paedophile ring prompted a multimillion-pound police inquiry gave Scotland Yard a list of potential abusers after being shown a series of photographs by a journalist, a court has been told.

Carl Beech is accused of making a string of false allegations about being among the victims of a group of senior figures in politics, the military and the intelligence services whom he claimed raped, kidnapped and murdered boys in the late 1970s and early 80s.

The former nurse met the Labour deputy leader, Tom Watson, a retired social worker, Peter McKelvie, and a journalist, Mark Conrad, in the months before he came forward to the Metropolitan police in October 2014, a court heard.

Beech, from Gloucester, had initially gone to Wiltshire police in late 2012. The force dropped its inquiry after he named only his late stepfather, Maj Raymond Beech, and Jimmy Savile as alleged abusers in the group.

On Wednesday, in the second week of Beech’s trial at Newcastle crown court, jurors heard how Beech approached the Met after being given an officer’s contact details by the investigative news website Exaro News.

Beech emailed Det Sgt James Townly, of the Met’s specialist operations unit, in October 2014 claiming he could help with the force’s investigation into high-ranking paedophiles operating out of Dolphin Square in London.

Beech asked if they could meet with Conrad present as he was nervous and needed to feel safe. The court heard that they met at a Gloucestershire police station for up to 30 minutes where Beech said he had been undergoing therapy since 2012 and was ready to speak again to police. Beech gave the detective a list of typed names, some of which were underlined.

In a recorded police interview conducted later that month, Beech said he had learned of a survivors website, The Tangled Web, and had begun blogging about his own experiences. He said he had been careful not to “name names”.

Conrad had seen the posts and contacted the site to obtain Beech’s details, and the pair had met in London after Beech had read previous Exaro stories. He wanted to know if there were other victims, Beech told police.

“Peter McKelvie and Tom Watson also formed part of a little group that was supporting me and put my information out there to encourage other people to come forward, hence the piece they did on Dolphin Square,” he said.

Beech said he had met Watson in his office and spoken to him at length. Though he described the experience of dealing with Conrad as positive, he said he found it “incredibly frustrating” as the reporter was aware he could not share certain information with him, the court heard.

The detective agreed with Beech that journalists had to protect the integrity of the investigation, adding: “It’s quite lucky someone like Mark is aware of that.”

Conrad had shown Beech photographs of people “to see if there was anyone that I recognised”, the former health worker explained in the interview.

Beech told Townly: “He did not go into any detail and the fact that there would be lots of them, but it was something they had to do in a particular way, that he couldn’t be there whilst I did it.

“Then I was just asked to mark on them if I recognised them, and if I did recognise them and they took part in the abuse. Then he had a whole bunch of photos that I just looked through.”

Beech added: “I picked them out, I didn’t know either their first name or their surname, some of them I knew what they did. That made a difference. He [Conrad] has not told me how he has found out who they were.

“It really helps me because it fills another blank, it just puts another piece of the jigsaw in place, but it’s annoying and he knows that.”

In the interview with Townly, Beech also claimed he had been tortured by Savile and the heads of MI5 and MI6.

Beech said his feet were jabbed with sharp objects and burned with a lighter, his head was held underwater and he was given electric shocks. Spiders were tipped over him during the abuse sessions, giving him a fear of the creatures, he said.

Beech described the gang as “sadistic”, adding: “They were trying to find new ways to inflict pain, terror, fear. Some of them liked to see me and others in pain.”

He said “Michael and Maurice” – who the jury has previously been told were Michael Hanley, a former head of MI5, and Maurice Oldfield, a former MI6 chief – would “instigate things”.

“They would tell the others what to do, but they wouldn’t do it themselves,” he said. “Jimmy Savile was nasty, but I only met him a couple of times.”

The trial has heard that Beech alleged he was abused by a murderous VIP group that included the former prime minister Edward Heath, the former home secretary Leon Brittan, Field Marshal Lord Bramall and the former Conservative MP Harvey Proctor, among others.

Beech, 51, faces 12 counts of perverting the course of justice from December 2012 to March 2016, and one count of fraud over a £22,000 criminal compensation payout he received.

He is accused of making a false allegation of witnessing the murder of a child by Proctor and falsely claiming to have witnessed the murder of two other children. He denies all the charges.

Last week the court was told that Beech himself was a “committed and manipulative paedophile” who at the same time as he was claiming to police to be a victim of abuse viewed indecent images of young boys and covertly recorded a child using the toilet.

The trial, which is expected to last up to three months, continues.