The detective told him six people were under investigation including former NoW editor Andy Coulson and reporter Sean Hoare, Mr Wood said.

BBC: Detective April Casburn 'offered NoW leaks for cash'

In a New York Times article last year former News of the World journalist Sean Hoare alleged that phone hacking was common practice at the newspaper.

CNN: Hacking scandal exposed secrets at Murdoch's tabloid

One of the few sources who went on the record in the Times article, former News of the World journalist Sean Hoare, said Coulson, then his boss at the tabloid, "actively encouraged me" to hack into the voice mails of public figures to get stories for the News of the World.

CNN: STORY HIGHLIGHTS