Sir Frederick Barclay and his identical twin, Sir David, have built one of the world’s wealthiest business empires, incorporating The Daily Telegraph, delivery service company Yodel and The Ritz London. The billionaire brothers, 85, are notoriously private, splitting their time between Monaco and a mock-Gothic castle on the Channel Island of Brecqhou.

A very public feud is currently playing out between the two tycoons, largely down to the sale of The Ritz hotel in London. Sir Frederick, along with his daughter Amanda, has taken legal action against three of Sir David’s sons, Alistair, Aidan and Howard. He has accused his nephews of perpetrating “commercial espionage on a grand scale” by furtively taping 1,000 private conversations, totalling 150 hours of recordings.

At an earlier court hearing, it was claimed that Alistair Barclay was caught bugging the conservatory of The Ritz, where Sir Frederick held many of his meetings, while smoking cigars.

Sir Frederick has also cast doubt over the recent sale of The Ritz, claiming it has been sold at ‘half the market price.’ The new proprietor is Abdulhadi Mana Al-Hajri, a 40-year old business tycoon who is also brother-in-law to Sheikh Hamad bin Jassim bin Jaber al-Thani, the Emir of Qatar. Al-Hajri reportedly paid £800m for the hotel, which still makes it the most expensive hotel in the world.

Sir Frederick has claimed that another Saudi suitor, Sidra Capital, previously offered £1.3b. His nephew, Aiden, has dismissed this figure as fanciful. The case continues.