A retired police officer who was with Yvonne Fletcher when she was shot and killed policing a protest has offered a reward to help catch the vandal who splashed white paint on her memorial.

The memorial in St James’s Square where she was gunned down at a demonstration against Colonel Muammar Gaddafi was one of five statues targeted in a spate of vandalism.

Former Metropolitan Police officer John Murray was policing the protest outside the Libyan People’s Bureau in the square in central London on April 17, 1984, when a gunman opened fire.

Mr Murray was standing next to 25-year-old Pc Fletcher when she was shot and promised her as she lay dying that he would find her killer .

The memorial to murdered police officer Yvonne Fletcher in St James's Square
The memorial to murdered police officer Yvonne Fletcher in St James’s Square is one of five memorials and statues that were vandalised (Met Police/PA Images)

The 63-year-old from Chingford said on Friday he is putting up a £100 reward from his pension for any information leading to the arrest and conviction of those responsible for the “heinous act” of vandalism.

Mr Murray said: “It’s disgraceful, when I saw the photograph I was just gutted.

“I go there once a year to lay flowers and I have done for the last 34 years.

“Because I was standing next to her that day and we changed places three or four times I think if we had done it once more it could have been me.

CCTV images issued by the Metropolitan Police of a person officers wish to trace
CCTV images issued by the Metropolitan Police of a person officers wish to trace (Met Police/PA Images)

“When I was with her I promised I would find out what happened.

“I regard it (the memorial) as almost a personal shrine, I made a promise to find out what had happened and every time I go there I repeat those words.”

No one has been brought to justice in connection with the murder of Pc Fletcher, with a suspect being released from bail in without charge and told the probe against him would not proceed “at this time”, the Metropolitan Police said in 2017.

A decision was made that crucial material cannot be used in court on the grounds of national security.

The Met is currently trying to trace the memorial vandal who is believed to have worn ski goggles and a face mask as he splashed white paint on five statues in central London.

The figures of Franklin D Roosevelt and Winston Churchill on the Allies sculpture in New Bond Street, London, which has been vandalised with white paint
The figures of Franklin D Roosevelt and Winston Churchill on the Allies sculpture in New Bond Street, London, which has been vandalised with white paint (Kirsty O’Connor/PA Images)

As well as the Yvonne Fletcher Memorial the vandal targeted the “Allies Statue” of Second World War prime minister Sir Winston Churchill and his US counterpart Franklin D Roosevelt in New Bond Street.

Also targeted were the Canada Memorial in Green Park, the Royal Marines Graspan Memorial on The Mall and Bomber Command Memorial in London’s Green Park.

Police believe the suspect first struck at the Bomber Command Memorial before heading along the Mall towards Trafalgar Square, passing Canada House in the direction of St James’s Square, before ending on Jermyn Street.

The force said it received reports of the vandalism on Sunday and Monday and is treating the incidents as linked.

Detectives are trawling through CCTV and appealing for information and witnesses.