Ex-MP tells inquiry Post Office ran a ‘behind-the-scenes deception process’

James Arbuthnot arriving to testify at the Post Office inquiry. Photograph: Carl Court/Getty Images

A former MP has told a public inquiry that the Post Office appeared to have been operating a “behind-the-scenes deception process” about the reliability of its faulty Horizon computer system.

James Arbuthnot, who is now a Conservative peer, began campaigning for post office operators in 2009 after taking up the case of Jo Hamilton, who was wrongly convicted of theft.