The future imprisonment of the Lockerbie bomber remains in the hands of the Scottish judiciary and Scottish ministers, even after a deal between Tripoli and the UK Government that could pave the way for his transfer to Libya.

The pledge from Whitehall comes after the two countries' recent agreement on prisoner transfer which specifically says that Scottish authorities have control over the future of prisoners north of the border, without naming the only Libyan held in a Scottish jail, Abdelbaset Ali Mohmed al Megrahi.

However, the issue has once again sparked tensions between the Scottish Government and Whitehall, with an accusation by Alex Salmond at the weekend that a £450m deal recently struck between the Libyan government and British-based oil giant BP has been linked to Megrahi's possible transfer from Greenock prison.

The row began in the early weeks of the SNP administration last year, when it emerged Tony Blair had discussed prisoner transfer when still prime minister and visiting Libya, but without consulting Scottish legal authorities.

The SNP asked Whitehall negotiators that the prisoner transfer agreement should specifically exclude Megrahi, but the UK Government found their Tripoli counterparts were not willing to break with convention and create a treaty with reference to a specific convict.

Holyrood ministers are "strongly opposed" to a transfer of Megrahi, convicted of killing 270 people in the 1988 bombing of Pan Am flight 103 over Lockerbie.

A spokesman for Mr Salmond said allegations that Megrahi's future was tied up with the BP deal are "very serious".

A Whitehall source responded last night that it remains the case that Scottish ministers will have the last word on any possible transfer.

While Megrahi appeals his case, he could not be transferred, and, whatever the treaty says, a refusal to transfer could be subject to judicial review under human rights law.