Hilton hotels recruited Starwood Hotel staff and encouraged them to raid the company computers before they left.

According to court papers Starwood Hotel claims that two of its former directors "directly and through other Starwood luxury brand employees they recruited to Hilton, nicked more than 100,000 electronic files before and after they joined Hilton".

Ross Klein and Amar Lalvani, who had developed Starwood's W brand, used the information to develop Hilton's new boutique brand, Denizen, which was announced just six weeks ago.

What gave the game away was that one of the stolen files contained references to a W Hotel concept called 'zen den'. Starwood said that it was the clearest imaginable case of corporate espionage, theft of trade secrets, unfair competition and computer fraud.

Hilton said that the lawsuit is without merit and will vigorously defend itself.