Richard Caring is believed to be leading the early pack of suitors for the American embassy in Grosvenor Square, London. Sunday Times

Although not officially for sale, the US State Department has instructed Cushman & Wakefield to search for a new home.

If it came on to the market the site could fetch more than £500m. Located in a prime enclave of central London, the land could become home to luxury residential apartments.

Rag-trade entrepreneur Caring bought the former US Navy headquarters on the site for £250m this year. He also owns the Ivy and Le Caprice restaurants, the Wentworth golf club in Surrey, and Annabel’s, the London nightclub.