The luxurious Ritz hotel in London has been sold to a Qatari investor, prompting Frederick Barclay to threaten legal action as the feud over the family’s billions in assets deepens.

The investor has agreed to buy the Ritz, the storied 115-year-old property that is the crown jewel in the twin Barclay brothers’ empire, which includes the Telegraph and online retailer the Very Group (previously known as Shop Direct and, before that, Littlewoods) and delivery firm Yodel.

London-based legal firm Macfarlanes said that one of its private Qatari investors had bought the hotel, which David and Frederick Barclay purchased for £75m in 1995. The sale price is unknown, but it had been touted at about £750m.

“It is a privilege to become the owner of the iconic Ritz Hotel and have the opportunity to build on its innate style and grand traditions,” said a spokesman for the new owner, which has not been named. “During this Covid-19 crisis, our first priority is towards the staff of the Ritz, who together are the essence of the Ritz’s 115-year-old reputation. Once this pandemic has passed, we look forward to re-opening the hotel and to sharing our longer-term plans.”

Sir Fredrick Barclay, who along with his daughter Amanda is in a bitter battle with his brother’s side of the family over the family assets, said the spread of the virus had been used to push through the sale.

Frederick, who has threatened to sue if a sale of the Ritz goes through for less than £1bn, has expressed outrage at not being consulted on the sale.

“This deal, if it has occurred, appears to have been pushed through in the middle of the coronavirus crisis in the hope that it will be uncontested,” said a spokesman for Sir Frederick Barclay.

Relations between the two sides of the Barclay brothers family have fallen apart since Fredrick’s nephew was caught handling a recording device in the conservatory of the Ritz, where Fredrick often conducts meetings, according to court papers.

“We are surprised and perturbed by the announcement that the Ritz hotel has allegedly been sold,” said a spokesman for Frederick Barclay. “We have neither consulted nor have we approved this sale. As we outlined earlier this month, any potential purchaser will face significant litigation if this deal is not approved by all sides.”

The family of Frederick’s brother, David, handles the day-to-day running and two of his sons, Aidan and Howard, control the Barclays empire as directors of Ellerman Investments Ltd, the holding company of the Barclays UK assets.

“We are pleased to have agreed a sale of the Ritz that secures great value for all shareholders, following a rigorous process led by independent advisers,” said a spokesman for Ellerman Investments Ltd.

“The buyer is committed to investing in the Ritz and its staff for the long-term, ensuring a bright future for this unique asset. We also note that neither Sir Frederick nor Amanda Barclay have any relevant legal interest which would allow them to disrupt the sale.”