Andy Coulson's instruction "Do his phone" was not an instruction to hack a phone, he told the Old Bailey today.

The former tabloid editor said that instead he was requesting a check of a reporter's phone data to see if he was leaking the News of the World's stories to rivals.

Mr Coulson sent the instruction on 20 May 2006 during an email conversation with a senior NoW journalist about a forthcoming exclusive on Calum Best, a two-time contestant on Celebrity Love Island and the son of footballer George Best.

Mr Coulson wrote: "You think Calum a leak?", to which the executive replied that Mr Best was "bragging I have close mates inside NoW".

Asked what he had meant by his subsequent email response, Mr Coulson told the court: "I was in no doubt that this was not an instruction to hack anybody's phone."

I remember what this was because it was Rav [Singh] and he was a friend of mine and I remembering authorising the request for billing data for Rav."

Ultimately, Mr Coulson told the court: "No evidence was ever put in front of me that Rav was definitively leaking stories."

The court has previously been told the News of the World's managing editor, Stuart Kuttner, received a copy of Mr Singh's billing data nine days earlier, on 11 May 2006.

Mr Coulson told the court that by sending his "Do his phone" email he was "re-emphasising" that earlier request.

He, Mr Kuttner and fellow former NoW editor Rebekah Brooks deny conspiring to hack phones. The case will resume on Tuesday, when Mr Coulson continues his evidence.