British Prime Minister David Cameron's communications chief has been questioned by police over allegations of phone-hacking when he edited a tabloid newspaper, it was confirmed. Downing Street said Andy Coulson voluntarily attended a meeting with officers from London's Metropolitan Police on Thursday and was interviewed as a witness.Coulson edited the News of the World at a time when the royal correspondent of the Sunday tabloid was jailed for conspiracy to access mobile phone messages involving Princes William and Harry. While Coulson resigned from the newspaper in 2007 over the affair, he has always insisted he did not know about the phone-hacking or authorise its use. A police investigation into the phone-hacking was revived after a former reporter at the tabloid, Sean Hoare, told the New York Times in September that Coulson had "actively encouraged" him to hack phone messages.