The man who has fought to find WPC Yvonne Fletcher's killer has told ITV News he is demanding answers after new details of Libyan warnings.
Two detectives from the Metropolitan Police have visited Libya as part of the investigation into WPc Yvonne Fletcher's killing.
Scotland Yard are to send a team of detectives to Libya to seek out new information which might lead to the killers of Wpc Yvonne Fletcher
Libyan justice minister Salah al Marghani has said the country is offering Britain full transparency and help in bringing WPC Yvonne Fletcher's killer to justice.
"It is another crime of the Gaddafi regime and there is full cooperation in this case and we have 100 per cent open lines with the UK on these issues," Mr al Marghani said.
Newly released government files have shown Libya twice warned the UK of potential violence on the eve of the shooting of Ms Fletcher outside the Libyan People's Bureau in London in 1984.
The gunman who fired the fatal shot from inside the embassy has never been identified.
The former British ambassador in Tripoli has told ITV News he took a threat of violence on the eve of the shooting of WPc Yvonne Fletcher "seriously" after it was revealed he bet a Libyan diplomat that nothing would happen.
Oliver Miles was summoned to the Libyan foreign ministry shortly after midnight on April 17 1984 to receive a warning of possible violence if a planned demonstration by opponents of Colonel Gaddafi went ahead that day outside the Libyan People's Bureau in London.
Mr Miles filed a telegram to the Foreign Office (FCO) reporting the warning, one of a number of documents released under the 30-year rule by the National Archives.
Other papers show two officials from the People's Bureau also telephoned the FCO to express concern about the demonstration the next day.
"I did take it seriously and that's why I reported it to London," Mr Miles told ITV News. "I didn't know, of course, that there was going to be a shooting. I thought they were simply trying to have the demonstration stopped."
Newly-released government files have revealed the Foreign Office was warned about potential violence the night before WPc Yvonne Fletcher was shot outside the Libyan Embassy in London.
Documents released under the 30-year rule show Libyan officials said they "would not be held responsible" if the planned protest went ahead.
However the warnings seem to have been regarded as little more than typical Libyan bluster - with Britain's ambassador even placing a bet that nothing would come of it.
The Metropolitan Police has revealed that two detectives from its Counter-terrorism Command have visited Libya to discuss the ongoing investigation into the murder of WPc Yvonne Fletcher. The Detective Superintendent and Detective Inspector met Libyan officials in Tripoli.
WPc Fletcher was shot dead when policing a demonstration outside the Libyan Peoples' Bureau in St James's Square in April 1984. The bullet was fired from the building but it was never established who pulled the trigger.
Mr El-Keib worked with the opposition while in exile during Muammar Gaddafi's dictatorship and said he knew some of those involved in the demonstration.
– Libyan prime minister Abdurrahim El-Keib
The Fletcher case is a case that is close to my heart personally.
I had friends who were demonstrating that day next to the embassy.
It is a sad story.
It is very unfortunate that it has anything to do with the Libyan people.
I am here to tell you that we will work very closely together to resolve anything related to that issue.
Visas for the Met detectives to travel to the war-torn country have been cleared but no exact date for their trip has been released yet.
After laying the floral tribute, Mr El-Keib gave a talk at nearby Chatham House, the independent policy institute, as part of his two-day visit.
Libyan prime minister Abdurrahim El-Keib today laid a wreath of white roses and carnations at the spot where policewoman Yvonne Fletcher was shot dead outside the country's London embassy in 1984.
Libyan PM due to lay wreath soon at place where WPC Yvonne Fletcher was shot dead outside Libyan Embassy in '84
A former colleague of Wpc Yvonne Fletcher who was murdered more than two decades ago has told ITV's Daybreak that he was "hopeful" that her killers would be bought to justice. John Murray said he had been "pressing" for further investigation into the case for the last 28 years.