David Cameron's communications director Andy Coulson has been questioned by police investigating allegations of phone-hacking at the News of the World, it has been confirmed.

Downing Street said Mr Coulson attended a meeting with Metropolitan Police officers voluntarily on Thursday and was interviewed as a witness.

Mr Coulson was editor of the Sunday newspaper at the time when one of its reporters was jailed for conspiracy to access phone messages involving Prince William and Harry, but has always insisted he did not know about or authorise the activity.

A Metropolitan Police inquiry was revived following an investigation by the New York Times earlier this year which alleged that the practice was more widespread than previously admitted.

A Downing Street spokesman said: "Andy Coulson voluntarily attended a meeting with Metropolitan Police officers on Thursday morning at a solicitor's office in London.

"Mr Coulson - who first offered to meet the police two months ago - was interviewed as a witness and was not cautioned or arrested."

Scotland Yard said in a statement: "We do not discuss persons interviewed as potential witnesses."