Senator 'misunderstands' says MacAskill

The move led by Senator Robert Menendez of New Jersey has come as he and three colleagues pushing for an inquiry into the release a year ago have become frustrated over the failure of UK and Scottish ministers past and present to appear before a Senate committee.

They believe the decision to release Abdelbaset Ali Mohmed al-Megrahi could have been linked to an oil deal between BP and Libya. The oil giant has already admitted lobbying for a prisoner transfer agreement (PTA) between the UK and Libya, but the company's chairman Lord Browne repeated yesterday on a visit to Edinburgh that it had never lobbied directly for Megrahi's release or approached the Scottish Government.

Senators are now calling on doctors or lawyers linked to the case to come forward and provide evidence and have promised to keep correspondence from government officials acting as whistle-blowers confidential.

But a spokesman for Justice Secretary Kenny MacAskill argued that the senators continue to misunderstand the nature of the release. He pointed out that the PTA was rejected by Mr MacAskill and he suggested that Senator Menendez had gone out on a limb.

He said: "Senator Menendez appears now to be acting on his own account, rather than on behalf of the foreign relations committee.

"The senator and his three colleagues have written to the Foreign Secretary concerning possible commercial influence in the UK government's decision to sign a Prisoner Transfer Agreement with Libya, and indeed have raised a new question concerning arms deals.

"Clearly, the Scottish Government has no knowledge of any of these matters, and this fully vindicates our staunch opposition to the PTA."