The company which runs the exclusive Carnegie Club resort at Skibo Castle near Dornoch slid further into the red in its 2014/15 trading year.
Accounts lodged at Companies House reveal Skibo Ltd suffered pre-tax losses of £1.53million during the 12 months to March 31, compared with losses of £636,000 the year before.
But turnover rose by more than £1million to £9.8million in the latest period and bosses said they were “satisfied” with the overall financial performance.
The business has been loss-making for years – it last made profits during the 15-month trading period to March 31, 2006.
But its owner, multimillionaire US-based fund manager Ellis Short, has deep pockets.
Since the 2014/15 year-end, Skibo has issued nearly 1million shares to its Bermuda-based investment vehicle Scytherbolle in an attempt to reduce loan and interest liabilities which by March 31 had ballooned to more than £16.3million.
In its accounts, Skibo said it still owed Scytherbolle £7.2million, with the repayment deadline having been extended to April 2024.
Mr Short, who also owns and is chairman of English Premiership football club Sunderland, bought the Highland retreat of the rich and famous in 2003 for a reported £23million.
It was previously owned by US investment fund Westbrook Partners and UK-based entrepreneur Peter de Savary, who bought castle on the estate at Clashmore in July, 1990, restored it and turned it into the exclusive private members’ club.
The Carnegie Club prides itself on providing privacy and staff never reveal who has stayed there.
Past guests of the castle include Rudyard Kipling, the Rockefellers and King Edward VII.
It was thrown into the spotlight in 2000 when pop icon Madonna married film director Guy Ritchie there. Their nuptials attracted massive coverage and dramatically increased the number of visitors to the Dornoch area.
Actress Ashley Judd and racing-driver Dario Franchitti followed suit in 2001 and pop star Robbie Williams celebrated his 30th birthday at the castle in 2004.
Other visitors have included ex-US presidents George Bush senior and Bill Clinton, Prince Andrew, Microsoft’s Bill Gates, Michael Douglas and Catherine Zeta Jones, Sir Sean Connery, Jack Nicholson, Bob Geldof, Ted Danson and Mick Jagger.
Many of the Carnegie Club’s famous guests, including Madonna and Robbie Williams, have planted trees in the castle grounds to commemorate their visits.