Lockerbie bomber al-Megrahi was guilty of 1988 attack, says Scotland's top prosecutor

Scotland’s top prosecutor has insisted that Abdelbaset al-Megrahi was guilty of killing 270 people in the Lockerbie bombing despite him protesting his innocence up until his death two years ago.

Lord Advocate Frank Mulholland said there has been no investigator or prosecutor that had ever disputed the validity of the evidence used to convict al-Megrahi, who was the only person convicted in 2001 of blowing up a Pan Am plane over the south west of Scotland in 1988.

His part in the bombing has been called into question in a series of books, documentaries and testimonies to the Scottish Parliament with a petition seeking "Justice For Megrahi", backed by politicians and even family members of some victims, remaining on Holyrood's books.

During a memorial service in Washington, Mr Mulholland is expected to reaffirm a commitment for finding any other accomplices by saying: “The Crown will never give up the fight to secure justice for the families of those who died.”

“We remain committed to this investigation and our focus remains on the evidence, and not on speculation and supposition,” he is to add.

Former Liberal Democrat leader Sir Menzies Campbell defended the judges’ decision in the face of criticism from campaigners.

He said: “It is a curious feature of this case that those who argued most vehemently for a special court to be set up to deal with the case are now among the most vociferous critics of its verdict.”

Lamin Fhimah, a former station manager at Luqa Airport in Malta, was acquitted of 270 counts of murder on 31 January 2001.

Al-Megrahi was unanimously found guilty and was sentenced to life before being released in 2009 as he was dying of terminal prostate cancer aged 60.

The late Libyan leader Muammar Gaddafi accepted responsibility in 2003 for the attack and paid compensation to the victims’ families, however he insisted that he had never ordered it to happen.