A retired police constable who was standing next to police officer Yvonne Fletcher when she was shot dead 31 years ago today is still fighting for justice. 

John Murray, of Norton Close in Chingford, was policing the anti-Gaddafi protest outside the Libyan embassy in St James's Square in central London on April 17 1984 when a gunman opened fire.  

Mr Murray, 59, cradled Yvonne as she lay dying in front of protestors from a single shot that pierced straight through her elbow and into her abdomen.

No one has even been arrested or convicted of her murder, or held accountable for injuring 10 protestors. 

However, in 1999 Colonel Muammar Gaddafi's government accepted responsibility for her death and agreed to pay £250,000 compensation to her family. 

After the shooting, prime suspect Matouk Mohamed Matouk, a top-ranking Libyan official was smuggled back to Libya under diplomatic immunity laws where he presided over Libya’s nuclear programme and rose to the position of deputy prime minister.

He is still alive today and the Metropolitan Police Service have said they "remain committed" to finding WPC Yvonne Fletcher's murderer. 

Mr Murray, promised the 25-year-old as she lay dying in the ambulance to Westminster Hospital and as carried her coffin at her funeral in Salisbury Cathedral that he would find her killer. 

He has travelled to Libya on more than five occasions since Gaddafi's regime fell and met with Matouk in December. 

"I have run a lone campaign for justice for 31 years," he said.

"We were there to protect the embassy but Yvonne was shot from the embassy.

"I believe this is the only case where a PC murdered on duty remains unsolved.

"With all the new information started to come out, it is an ideal time to keep the momentum going.

"If I and my supporters do not continue fighting for justice, I have no doubt Yvonne would be a distant memory because people want to forget."

Mr Murray has criticised successive UK governments and the intelligence service following recent claims GCHQ had prior warning of violence at the protest. 

Last year, Mike Arnold, a technology officer at GCHQ at the time alleged an order to "cover the streets of London with blood" by Gaddafi was intercepted, decoded and translated but was not acted upon.  

To mark the 31st anniversary, Mr Murray organised a memorial service at St James's Square this morning where wreaths were laid by himself, Westminster police, and several police associations.