The top civil servant investigating "wild allegations" that national security was put at risk when a friend of the Defence Secretary was allowed repeated access to government buildings will focus on what information was potentially exposed during his visits.
Liam Fox asked the Ministry of Defence's permanent secretary, Ursula Brennan, to look into claims security could have been compromised after Adam Werritty, his former flatmate, made 14 visits to the department over 16 months despite not being employed by the Government.
Details of what the inquiry will look into were released by the department tonight and initial findings, which will be made public, will be reported to the Secretary of State and the head of the civil service, Sir Gus O'Donnell, on October 21.
The investigation will "examine the access to departmental premises and information afforded to Mr Werritty, and establish that there has been no breach of security", an MoD statement said.
It will also turn the spotlight on the role of officials to check whether the "department acted in accordance with guidance on propriety".
The review will come up with recommendations on "any action necessary in the light of these inquiries, including any action necessary to clarify the current guidance".
Ms Brennan raised concerns about whether Dr Fox and Mr Werritty's friendship had strayed into official government business in August, according to the Guardian.
An MoD spokesman said Secretaries of State and permanent secretaries "discussed many matters on a routine basis" but would not "get into specifics about those discussions".
Dr Fox has come under pressure in recent days over his relationship with Mr Werritty, who was best man at his wedding.
It emerged that the friend joined the Defence Secretary on an official visit to Sri Lanka, despite previous claims that he had not travelled with him on official visits overseas.
The Defence Secretary today 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 have had a long relationship in Sri Lanka, trying to get co-ordination of peace efforts there. That's a perfectly reasonable thing to do.
"Because there have been some allegations of security leaks and so on, I've asked the permanent secretary to look into that for me."
He added: "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".
Dr 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."