Chris Pharo (top left) is accused of aiding and abetting misconduct in a public office between 2002 and 2011. Credit: Youtube.

The Sun's head of news, Chris Pharo, only learnt a senior reporter had been paying a police officer when he was arrested, he told his trial today.

Giving evidence at the Old Bailey, Mr Pharo said the Thames Valley reporter Jamie Pyatt and other journalists never identified their sources to him.

The court has heard that Mr Pharo received emails from Mr Pyatt requesting cash payments of thousands of pounds subsequently made to a Surrey police officer.

Asked when he first learnt that Mr Pyatt's source, Officer 2044, was a serving police officer, Mr Pharo said he wasn't exactly sure, but it was "after I was arrested"

Entering the witness box for the third day, the Sun's Assistant Editor (News) insisted his role in the payment system was limited to "valuing" stories for which payments was sought. He then passing the requests up the line for authorisation.

Asked how it felt to have known that he played a role in the payments to Officer 2044, Mr Pyatt told Court 13: "I was shocked..."

Cross-examining, prosecutor Julian Christopher QC took the executive through a series of Mr Pyatt's emails asking for cash payments for his police source.

Asked what he would have made of the request for £500, Mr Pharo told the Old Bailey: "I wouldn't necessarily have taken it at face value. It wasn't my job to police the Sun newsroom."

He added: "I don't recall reading this email."

Another time Mr Pyatt requested a cash payment for a story about the glamour model Jordan's (now Katie Price's) boyfriend being arrested for drink-driving, telling Mr Pharo: "He [the source] gave me every cough and spit from the arrest."

"That's plainly a police officer, isn't it?", Mr Christopher suggested, to which Mr Pharo replied: "I disagree."

He said Jordan's entourage was "notoriously leaky".

When Mr Christoher pointed out that Mr Pyatt had said his source had "screened" the details, Mr Pharo said many people used computers.

Mr Christopher demanded: "The full truth is that both of you knew full well that this was a serving police officer?"

Mr Pharo replied: "That's not true."

He explained there were "a multitude of reasons" why contacts wanted to be paid in cash. 

Asked whether paying a police officer to break the rules would have caused him "any concern," Mr Pharo replied: "It wasn't my job to police the Sun newsroom. It wasn't my job to pull people up on things like this."

He said he did not believe journalists who claimed that they were seeking cash payments for "a cop" or "a serving police officer" or a "Chelsea copper" were actually paying police officers.

Mr Pharo, who ended his evidence at 1pm, had stayed silent at his police interview in 2012 on the advice of his lawyer.

He and Mr Pyatt deny aiding and abetting misconduct in a public office between 2002 and 2011. The case continues.

See openDemocracyUK's full series on the Sun trials here.