PC Yvonne Fletcher murder: British police visit Libya
Two Metropolitan Police detectives have visited Libya as part of the ongoing investigation into the murder of PC Yvonne Fletcher.
The officers travelled to Tripoli on Monday and returned on Wednesday.
A Met Police spokesman said they discussed with Libyan officials how to take the inquiry forward.
PC Fletcher, 25, was shot while policing a protest against the Muammar Gaddafi regime at the Libyan embassy in St James's Square in 1984.
The officers - a detective superintendent and a detective inspector - were from the Met's Counter Terrorism Command.
In a statement, the force said it hoped their "preliminary discussions" would pave the way for the Met and Libyan authorities to work together to identify PC Fletcher's killer.
The detectives will remain in regular contact with the policewoman's family who will be given an update about the visit, the force added.
British officers had previously been refused visas by the Libyan authorities for such a visit.
The bullets which killed PC Fletcher and injured 10 protesters came from inside the Libyan embassy, but no-one has ever been charged over the shootings.
Her death led to an 11-day siege of the building and the severing of diplomatic ties between the UK and Libya.
Last month, Libyan Prime Minister Abdurrahim El-Keib laid a wreath at the spot where she died, and held a private meeting with her family.
They said in a statement they "looked forward to the investigation progressing".