Adrian Prout, 49, who had always denied any part in Kate Prout’s disappearance, was taken by officers to their 276-acre farm in Redmarley, Gloucestershire, yesterday.
He was seen at the farm handcuffed to an officer as the search began.
Prout was convicted by a jury at Bristol Crown Court of murdering his 55-year-old wife after she vanished on Bonfire Night in 2007. Her body has never been found.
It is understood that he came clean about the killing to his fiancee Debbie Garlick after failing a lie detector test inside prison.
Police said they would carry out a detailed search of the area next week, but warned it was likely to last some time.
Detective Superintendent Simon Atkinson, of Gloucestershire Constabulary, said: “Yesterday morning we received some new and significant information in relation to the murder of Kate Prout.
“Yesterday afternoon two detectives paid a visit to the prison where Adrian Prout is being held.
“Adrian Prout has admitted to those detectives that he murdered Kate Prout – something which he had always denied – and has now suggested that he disposed of her body on Redhill Farm in Redmarley.”