Professor Robert Black QC has confirmed that under current international arrangements, a further "trial" of Abdebaset Ali Mohmed Al Megrahi cannot be convened without a new UN resolution, contrary to suggestions in US political circles that such a step could be taken.

Black has stepped in to quell what he has termed the "nonsense" surrounding proposals floated recently by US Senators and echoed in US media, which have included sending in Navy S.E.A.L "snatch squads" to kidnap and render Megrahi into US custody.

The Zeist trial was convened under the auspices of the UK and US Government and sanctioned by a series of UN Security Council resolutions.

"Both governments thereby undertook internationally binding obligations to comply with the legal processes thus set in motion. The United States cannot lawfully renounce those obligations either unilaterally or in conjunction with whatever new government it chooses to recognise in Libya," Black says.

"To have Abdelbaset Megrahi lawfully handed over to the US would require a further UN Security Council resolution. The United States, as a permanent member of the Security Council could, of course, propose such a resolution. But would the other members support it?"

Black has previously warned that the US could "simply ignore international legality (as it did, with the UK's supine support, in launching the invasion of Iraq) and seize Megrahi by force (with or without the connivance of a new Libyan regime)."  Writing on his blog today, he adds that under the US Constitution, the "binding international obligation" of the Zeist trial precludes any US court from trying Megrahi again, as that that would breach the international agreement.

"Moreover, during the Camp Zeist trial, US government lawyers sat amongst the prosecutors and when their presence was questioned the Crown Office responded that the Lord Advocate could select whomsoever he chose to form part of the prosecution team. It can be strongly argued that this active participation by United States officials, as part of the prosecution team, in a trial which the US co-sponsored, personally bars (estops) the US from instituting its own national criminal proceedings," he says.

He adds that a fresh US based trial could theoretically be convened, but only under a new UN Security Council resolution, adding that any "internal" legal amendment that sought to legislate for a retrial would be liable to be struck down under art VI, clause 2 of their Constitution.

An inquiry into the entire Pan Am 103 debacle is to be considered by the Holyrood Parliament's Justice Committee after an earlier referral from the Petitions Committee.