Yesterday saw the beginning of the high-drama court case, as the property developers called the behaviour of the Qataris “scandalous”.

In their typical bold style, the Candy brothers, Nick and Christian Candy, had planned to build a 13 acre modern development of luxury flats on the former Chelsea Barracks site near Sloane Square, London. However, the £3 billion development of 548 flats in 17 blocks never came to be, after the owner of the site, the Qatari royal family’s property firm, dropped the planning application.

It is thought that plans were withdrawn for the imposing Lord Rogers development after interference from Prince Charles, who is outspoken in his views against modern architecture.

Letters from the Princes of Wales to the head of Qatari Diar Real Estate Investment will be shown in the high court this week, although he will not be called upon as a witness.   

The Candy brothers have claimed that the Prince of Wales used his position to persuade the Qataris to shelve the lucrative project, and are now suing for £81 million.

Last March a letter was leaked from the prince to Qatar’s prime minister and the chairman of Qatari Diar, Sheikh Hamad bin Jasim, calling the “brutish development” unsympathetic and unsuitable.

Prince Charles also invited the Emir of Qatar and his wife, Sheikha Mozah Bint Nasser Al Missnesd, for tea at Clarence House a few weeks later, in May.

By June the project had been scrapped, leaving architect Lord Rogers to tell the Guardian newspaper: “I thought we were home and dry. I just don’t know what happened.”

A spokesman for Clarence House has stated: “Prince Charles is entitled to his private opinions. Any dispute between the Candys and the Qataris is for them to resolve, not us. The prince knows the emir and his wife extremely well and the meeting would have happened anyway as part of his royal and diplomatic role.”

The hearing, which is expected to last at least three weeks, continues.