LONDON – British police said Tuesday they have dropped a bid to prosecute a Libyan man over the 1984 killing of a London policewoman who was shot dead from inside the country's embassy.
The suspect was arrested in November 2015 in what police said was a significant development.
The Metropolitan Police said they had enough material to identify those responsible, but that the key evidence could not be presented to a court "for reasons of national security."
The force said the suspect has been freed from police bail and the case "will not be proceeded with at this time."
Constable Yvonne Fletcher was killed and 10 others wounded on April 17, 1984, when someone opened fire with a submachine gun from inside the Libyan People's Bureau in London. Fletcher was policing a large demonstration against Libyan dictator Moammar Gadhafi outside.
A 10-day siege followed the shooting before 30 people holed up inside were deported to Libya.
The shooting led to a 15-year rupture in diplomatic relations between Britain and Libya and helped seal Libya's reputation as a rogue state.
Britain and Libya restored ties in 1999 after Libya accepted responsibility for Fletcher's shooting, apologized and agreed to pay her family compensation
Police said Tuesday that the investigation into the "act of state-sponsored terrorism" would never be closed, "but the likelihood of finding further evidence, in Libya or elsewhere, is low."
Fletcher's family said in a statement that they were "deeply disappointed and frustrated" that no one could be prosecuted.