A telegram sent by Noel Coward to Agatha Christie from Bermuda in 1957 has been found hidden inside an old bureau while it was being restored, the BBC reported today.The BBC says the telegram congratulates the writer on her play ‘The Mousetrap’ breaking the record for the longest running show in London's West End - previously held by Mr Coward’s play ‘Blithe Spirit’.The bureau had been bought in an auction of items from Agatha Christie's former home in South Devon.Gloucestershire furniture restorer Clive Payne, who discovered the telegram when he took the back off the bureau, told the BBC he had been asked to repair it by the owner, who wishes to remain anonymous."The client rang me up and said he had a bureau which came from the estate of Agatha Christie which he'd recently purchased," he said.