An investigation has been launched into claims that national security was put at risk when the Defence Secretary, Liam Fox, allowed a friend access to the Ministry of Defence.
Dr Fox ordered the inquiry himself by asking Ursula Brennan, his permanent secretary and most senior official, to look into allegations concerning Adam Werritty, who was his best man and, according to reports, styles himself an adviser to the minister.
Dr Fox said: "A number of baseless accusations have been made in recent days. For the sake of clarity, I have asked my permanent secretary to establish whether there has been any breach of national security or the ministerial code. She will report back in due course."
Labour MPs have questioned Mr Werritty's role after it was revealed in parliamentary answers that he had visited Dr Fox at the ministry 14 times in 16 months.
The controversy deepened last night when The Guardian newspaper claimed that Mr Werritty was with the official delegation when Dr Fox arrived for a lecture during a visit to Sri Lanka in July.
Dr Fox had earlier insisted his friend had "not travelled with me on any official visit". Last night, the MoD said Mr Werritty was present for the event but was not part of the official party.