Legal discussions about a potentially crucial top secret document that could help clear the Lockerbie bomber should be heard in private, the appeal court in Edinburgh was told on Tuesday.

Britain's top legal officer in Scotland, Advocate General Neil Davidson, told three judges in the case that they should discuss whether the document should be made public behind closed doors and with specially-vetted lawyers.

Lawyers for the man convicted of the bombing, Abdelbaset Ali Mohmet Al-Megrahi, have not submitted their views, but Davidson said at the administrative hearing that it appeared they were against such a move.

Megrahi, a former Libyan intelligence officer, is seeking to overturn his conviction and 27-year sentence for bombing Pan Am Flight 103, which exploded over the southern Scottish town of Lockerbie on 19 December 1988.

A total of 270 people died — 259 on board the plane and 11 people on the ground — in what remains Britain's worst terrorist attack.

His lawyers have requested that the secret documents, provided by an unnamed foreign power and kept from his defence team at trial in 2002, be made public, maintaining there could be a miscarriage of justice if they are withheld.

One of the documents relates to the supply of timers which allegedly exploded the bomb and was pivotal to his conviction, a hearing last October was told.

Megrahi (55) lost a previous appeal against conviction in 2002.

His legal team have previously accused the British government in London of interfering in the separate Scottish legal system by seeking a ban on the document being made public.

The Herald newspaper in Glasgow last week said that appointment of security-cleared special advocates was unprecedented in Scottish legal history.

It added that "the tactic will fuel suspicions that the Crown is going to unusual lengths to preserve the UK's current diplomatic relations with other nations".

AFP