Police said that Lord Caithness kept several licenced sporting guns at their home near Chipping Norton, Oxfordshire. No suicide note from Lady Caithness, 40, has been found but police say no one is being sought in connection with her death.
Lord Caithness discovered the body in the bedroom of their home on Saturday evening, and resigned his government post on Sunday. He said that he wanted to spend more time with his children, Iona, 19, and Alexander, 12.
The inquest will be opened and adjourned at Oxford coroner's court today pending a full hearing at a later date. Lord Caithness, who has formally identified his wife's body, is not expected to attend.
Meanwhile, allegations about the private lives of other politicians continued to shake the Conservative Party.
The furore surrounding David Ashby, the MP for Leicestershire North-West, grew ever more bizarre as the day went on, with his wife, Silvana, appearing confused as to whether their marriage was over.
While Mr Ashby, 53, admitted sharing a bed in a French hotel with a male friend, he categorically denied allegations that they had had a homosexual relationship.
He said: 'We went to two hotels. In the first one we managed to find twin beds and at the second one we didn't. It doesn't make any bloody difference.' He said he had slept in the same bed as male friends on many occasions. Those who interpreted that as indicating homosexuality clearly had 'dirty minds'.
He said that recently he came to the conclusion that his marriage of 28 years must end and planned to separate from his wife, who was reported in newspaper stories as claiming that he had left her for a man.
Mrs Ashby, 51, initially said yesterday that it was too early to say whether they would stay together, later blamed unsocial parliamentary hours for their marriage breakdown and finally announced that she and her husband were going on holiday together.
Dr Ciaran Kilduff, the man linked with Mr Ashby in several newspaper reports, said that he was issuing writs for libel. He added: 'I have never had a homosexual relationship with Mr Ashby, nor with anyone else.'
Meanwhile two senior government ministers were at the centre of a gay smear campaign when voters in their constituencies were sent leaflets alleging that they were having a homosexual affair.
The leaflets, printed on pink paper, urged constituents to lobby the MPs to vote against a lowering of the age of consent for homosexuals to 16. Within 24 hours of them being posted, a right-wing activist credited with their publication denied being involved.
About 200 of the notices, entitled 'An Occasional Letter to the Electors of (the ministers' constituencies)' were sent to voters in the Home Counties and in London. Last night, the agent for one minister and a senior constituency worker for the other denied the allegations; the ministers refused to comment.Reuse content