The £1 million police investigation into allegations that Sir Edward Heath was a paedophile is being wound up amid claims it has found no evidence to justify tarnishing the former prime minister’s reputation.

Private investigators hired by police to help conduct the inquiry have been told contracts are not being renewed, according to sources.

The inquiry, codenamed Operation Conifer, will be closed in the coming weeks, but the report on its findings will remain confidential.

Friends of Sir Edward insisted that the Wiltshire police inquiry had found no evidence to implicate the Conservative politician.