A friend of murdered police officer Yvonne Fletcher who cradled her as she lay dying has launched a fundraising campaign for a private criminal prosecution on the 40th anniversary of her death.

John Murray, Ms Fletcher’s former colleague promised to find those responsible as he announced a new campaign to bring a case against key suspect Saleh Ibrahim Mabrouk, at a memorial on Wednesday.

Pc Fletcher, 25, was shot while policing a demonstration against the former Libyan leader Colonel Muammar Gaddafi outside his country’s embassy in St James’s Square, central London on April 17 1984.

Since then, no one has been held criminally responsible for her death.

The new case will include a request for Mr Mabrouk’s extradition to the UK to stand trial.

In November 2021, Mr Murray won a civil action at the High Court in London against Mr Mabrouk – a senior member of the pro-Gaddafi Libyan Revolutionary Committee that ran the embassy at the time.

In the ruling, High Court judge Mr Justice Martin Spencer said that Mr Mabrouk, who denied any wrongdoing, “clearly assisted in the commission of the shooting” and was jointly liable with the unknown gunmen.

Criminal and civil cases require different standards of proof, with criminal prosecutions requiring the higher standard of “beyond reasonable doubt”, whereas civil cases which can be ruled upon on “the balance of probabilities”.

Mr Mabrouk was arrested in 2015 in connection with Pc Fletcher’s death but two years later the Metropolitan Police said that, while detectives could identify those responsible, charges could not be brought as key evidence had been kept secret to protect national security.

Mr Murray, who has campaigned for decades to find “justice” for his friend, said: “The terrorist murder of Yvonne Fletcher 40 years ago on the 17 April 1984 was one of the worst atrocities executed by Gadaffi.

“To this very day the quest for justice for Yvonne continues and although we have had historic victories in both the High Court and Appeal court, the man who allegedly orchestrated Yvonne’s murder continues to live freely.

“If the CPS (Crown Prosecution Service) cannot or will not proceed with criminal charges, the only option available is to embark on our own legal action in the criminal courts.”

On the new campaign, Mr Murray told the PA news agency: “I’ve got no doubt that hopefully we’ll get that money.

“But what I’m hoping for is once these proceedings start that the CPS will see sense at last and possibly come in and either work with us and assist us to take over the whole case and take it forward to hearing.

“That will obviously cut down on costs and that’s quite good.”

Mr Murray said the civil case in the High Court had cost just over £250,000 and that lawyers have advised him that starting the private criminal prosecution will cost a minimum of around £165,000.

A memorial for Ms Fletcher was held on Wednesday morning and was attended by hundreds of people in central London in the place where she was shot.

A procession of former female police officers led by a solo bagpipe player preceded the memorial service in which Mr Murray described those present as his “family”.

Attendees laid flowers at the base of a memorial to Ms Fletcher at St James’ Square and the ceremony ended with the release of seven white doves in tribute to the fallen police officer.

Speaking at the memorial, Mr Murray said: “I will take a private criminal prosecution against Saleh Mabrouk. I will see him in a criminal court.

“Justice is what we will get for a fallen colleague because we will never and can never forget her,” he added.

Legal representatives for Mr Murray, Matthew Jury on behalf of McCue Jury and Partners, and Andrew Marshall on behalf of Edmonds Marshall McMahon, said in a statement: “It is a stain on the nation’s conscience that WPC Yvonne Fletcher’s alleged killer, Mabrouk, continues to live freely in Libya.

“This private prosecution should mean that Mabrouk will face a criminal trial and Yvonne will finally get the justice our country owes her.”