 Tchenguiz had bought the building for his Rotch property business in 2004 for about £140 million.Various activities were also conducted by MI5 at addresses on South Audley Street.In 1978, MI5 also occupied facilities at 1-4 Curzon Street, known as "Curzon Street House", for use by the registry, administration and technical services departments; that site was redeveloped in 1996.