The only man convicted of the Lockerbie bombing again protested his innocence as Scotland's law chief pledged to "find the answers" victims' families have been waiting for.

Two hundred and seventy people were killed when Pan Am Flight 103 exploded over the town of Lockerbie on November 21, 1988.

Abdelbaset al Megrahi was convicted of carrying out the bombing at a Scottish court sitting at Camp Zeist in the Netherlands in 2001 and sentenced to life imprisonment.

He was released on compassionate grounds in 2009 after he was diagnosed with terminal cancer.

But in what he said was his final interview, published in several UK newspapers, he reiterated his claim that he was not involved in the bombings.

The interview was reportedly filmed by investigator and former policeman George Thomson on Saturday. Megrahi said it would be the last he gave before his death.

In it, the Libyan said: "I am an innocent man. I am about to die and I ask now to be left in peace with my family."

He said he had "never seen" a Maltese shopkeeper whose identification was central to the conviction. Tony Gauci had identified Megrahi as buying clothes, the fragments of which were found among the wreckage of the flight.

The interview was published shortly after a memorial service marking the 23rd anniversary of the atrocity was held in the United States.

Scotland's Lord Advocate Frank Mulholland travelled to the US for the memorial and laid a wreath on behalf of the people of Scotland.

Mulholland said: "Justice has only partly been done. The evidence pointed to it being an act of state-sponsored terrorism.

"Megrahi was a member of the Libyan security service - it is risible to think that he acted alone. What we want to do is bring the others to book. A huge opportunity has opened up. It was very difficult when Gaddafi was alive and in power in Libya, and the answers are in Libya."