Defence Secretary Liam Fox has ordered an investigation into continuing claims surrounding the role of a controversial friend and adviser.
Dr Fox has asked his most senior official, permanent secretary Ursula Brennan, to look into what he describes as "wild allegations" concerning Adam Werritty.
In recent days Dr Fox has been accused of putting national security at risk by allowing Mr Werritty - a former flatmate who was best man at his wedding - access to the Ministry of Defence, even though he is not employed by the Government.
It has been reported Mr Werritty joined the Defence Secretary on an official visit to Sri Lanka, despite Dr Fox having previously said Mr Werritty did not travel with him on official visits overseas.
The Defence Secretary said he did attend a "private event" with his friend on the island nation after a picture of the pair was published in the Guardian.
He told BBC News: "It was organised by Adam Werritty and Mrs (Suganthie Wijayasuriya) Kadirgamar, who's the widow of the assassinated Tamil former foreign secretary of Sri Lanka.
"I've asked the permanent secretary to look into any of these wild allegations, and I'm very happy to stand by that investigation."
Mr Werritty has been a controversial figure in Whitehall. Despite having no official role he is reported to hand out business cards with a portcullis logo describing himself as "adviser to Rt Hon Liam Fox MP".
Mr Fox said: "I understand those cards are no longer used. I have made it very clear to him that it's unacceptable to carry a card saying that he is a personal adviser."
An MoD spokesman said: "Mr Werritty's meetings with the Secretary of State at the MoD have concerned entirely private matters, not to discuss MoD business. At no time has he had access to any classified MoD documents or information."