British police investigating the Lockerbie bombing are to visit Libya.

David Cameron announced that officers from the Dumfries and Galloway force had been granted permission to visit the country, at a joint press conference in Tripoli with his Libyan counterpart Ali Zeidan.

The Prime Minister said: "I am delighted that the Dumfries and Galloway Police team will be able to visit your country to look into the issues around the Lockerbie bombing."

The officers are expected to travel to Libya in March. It will be the first time police have been allowed to visit as part of the probe.

The move follows months of behind-the-scenes talks. Mr Cameron pointed out that police investigating the murder of Pc Yvonne Fletcher had been able to come to Tripoli three times since the revolution. That would have been "unthinkable" when Muammar Gaddafi was in power, he added.

On December 21 1988, 270 people were killed when Pan Am flight 103 exploded over Lockerbie. In 2001, Libyan Abdelbaset al-Megrahi was convicted of mass murder and sentenced to life imprisonment. He was released eight years later on compassionate grounds and he died in May last year.

In December last year the Libyan administration said it was preparing to release all files relating to the bombing. A formal request was sent to the Libyan government requesting access to the country for police and prosecutors involved in the bombing, in February last year.

A spokesman for Dumfries and Galloway Constabulary said: "It's the first time since the fall of the previous Libyan regime that officers will have the opportunity to make further inquiries in the country."

Metropolitan Police officers probing the shooting of Pc Fletcher during the Libyan embassy siege in 1984 are due back in Libya over the coming weeks, Downing Street sources said. The small Lockerbie investigation team from Dumfries and Galloway Police will be making initial contacts with the authorities in the country and discussing how their inquiry could proceed.

Mr Cameron added: "Do I want for all these cases for the truth to be uncovered, for justice to be done? Yes, of course."