Veteran campaigner Tam Dalyell has said that Libyan intelligence chief Moussa Koussa told him in 2001 that he had no involvement in the Pan Am 103 affair.

He further adds that the “duplicitous” Scottish Crown Office would be the “wrong people” to question him.

Dalyell’s statement comes amidst growing suspicion over Mr Koussa’s motives for travelling to London, and concern that the event is being carefully stage managed to be presented as a defection, when he may in fact be negotiating an "exit strategy" for Muammar Gadaffi.

Dalyell met at length with Koussa at an Inter Parliamentary Union conference in Syria in March 2001.

“He asked to see me and we met along with John Cummings, who was then the MP for Easington. He wanted to discuss how to bring Libya back into the international community,” Dalyell explained.

“Obviously, Lockerbie played a large part in our discussions, but when I asked him about it, he said ‘that was none of my doing'."

The day following his arrival in London, the Crown Office and Dumfries and Galloway Police made coordinated overtures to the media to suggest they were keen to speak to Mr Koussa over the Pan Am 103 event, despite their previous history of obstructing inquiries into the affair - most recently to the Holyrood Petitions committee which is considering whether a full inquiry should be opened - and failing to follow up new lines of inquiry that have arisen since Megrahi was convicted.

MSP Christine Grahame described Dumfries and Galloway Police Force’s efforts in connection with the case as “file management” last month.

“I think that two generations on, the officers at Dumfries and Galloway police force will be under terrible pressure to justify the investigation carried out by their predecessors,” Dalyell said.

“As I have said before, I believe that at times the Crown Office has been duplicitous about this. So they would be the wrong people to question him."

The Crown Office have refused to confirm whether they have yet to interview Mr Koussa, or whether a date has been agreed. The Times newspaper reported that the UK Government failed to rule out the possibility that Koussa might leave the country before investigations by the International Criminal Court are complete.

Paul Wilkinson, Emeritus Professor of International Relations at the University of St Andrews says it is possible he is involved in a “cunning effort to negotiate an end to the Nato air strikes and a route by which Gaddafi could retain power, at least over Western Libya.”

The Crown Office said they were still “liaising with the Foreign Office regarding an interview with Mr Koussa.”

“As with any ongoing investigation, we will not go into the details of our inquiries which includes the dates of interviews with any individuals,” they said.

The Crown Office have not interviewed former Libyan Justice Minister Mustafa Jelil, who claimed on his defection that Colonel Gadaffi ordered the Pan Am 103 event. Jalil has not offered any evidence to support his claim.

The Crown Office also did not interview UN explosives consultant John Wyatt, who conducted tests which undermined the Crown's claims that a semtex blast could have left traces of circuit board, which formed the key evidence in their case.

Instead the Crown Office issued a critical statement of Dr Wyatt, and did not engage with the key finding of his experiments.