The request comes after suggestions from a documentary arose that the process of awarding the contract have been rigged as successful bidder Ferguson Marine Engineering may have benefited from preferential treatment, Daily Business reports.

Scottish Tory spokesman, MSP Graham Simpson, said the deal “looks like corporate corruption.”

Mr Simpson added: “This alleged rigging of the contract, this potential fraud, has cost the country £250 million and it’s rising.”

Deputy First Minister, John Swinney, said he would rely on Audit Scotland to “establish any further inquiry that is required to be undertaken”.

A spokesman for Audit Scotland said that Stephen Boyle, the auditor-general, has the “full support” of John-Paul Marks, the permanent secretary to the Scottish government, and stated: “We will be looking at the substance of the allegations raised around procurement by the programme before deciding if further audit work is required.”