A man accused of murdering his millionairess wife said her attempts to save their marriage were “a complete sham”.

Robert Brown told Reading Crown Court he discovered a letter from Joanna Brown’s lawyers discussing divorce proceedings dated January 2007 – the same time the couple were supposed to be seeking marriage counselling.

Brown, 47, found the correspondence while trying to dig up financial information about his wife during their acrimonious divorce proceedings.

He said: “This was a smoking gun, this. This letter that she’d already gone to get legal advice, saying that she wanted to get divorced ... It’s a sham, a complete sham.”

British Airways pilot Brown, of Winkfield, Berkshire, had been taking sleeping pills in early 2010 as he struggled to cope with the stress of the split, the court heard.

He said: “I wasn’t feeling too great. I was losing a lot of sleep, I wasn’t sleeping at all well because of the unresolved issues that I had with the divorce.”

Brown went on: “I kept flying but sometimes I shouldn’t really have been, strictly speaking, but I couldn’t afford not to basically. I didn’t have many options. I had at the time had unpaid leave just to get by, just to give me breathing space.”

Joanna Brown, 46, formerly of Badger Hill, York, was allegedly bludgeoned to death with a claw hammer at the couple's mansion in Ascot, Berkshire on October 31 last year, and buried her body in Windsor Great Park.

The prosecution claims Brown dug a grave for his wife weeks before the alleged murder and buried her body in a plastic garden crate.

He admits killing her, but denies murder, and also denies obstructing a coroner from carrying out an inquest.

The trial continues.