Rupert Murdoch was “devastated” by the close relationship between his former wife Wendy Deng and Tony Blair after learning about the pair’s ties via his domestic staff, according to a book written by the mogul’s longest-serving editor.

In a new tell-all memoir, Chris Mitchell, the former editor-in-chief of The Australian newspaper, has revealed the pain endured by Mr Murdoch after learning about the "closeness" between his third wife and the former British Prime Minister.

“He was clearly lonely and struggling to sleep at night for the first few months after the separation,” Mr Mitchell writes.

“He rang much more often than he had previously. And he was frank about his sleep problems, sore back and the hurt he was feeling about what had happened between Wendi and Tony Blair.