The former royal editor of the News of the World has admitted he hacked the phones of Prince William and Kate Middleton on a combined total of 180 occasions.

Clive Goodman, who was jailed for four months in 2007 for phone hacking, told the Old Bailey he hacked the Duchess of Cambridge's phone 155 times, beginning in 2005, when he tapped into her conversations on Christmas Eve, Christmas Day and Boxing Day.

Goodman, who is now facing fresh charges, also hacked Prince William's phone 35 times and Prince Harry's on nine occasions.

The 56-year-old is one of several people on trial on phone hacking charges, along with former News of the World executives Rebekah Brooks and Andy Coulson. He denies two counts of conspiracy to commit misconduct in a public office.

The court also heard how Goodman intercepted Middleton's phone in August 2006, the day before he was arrested on phone hacking allegations.

He said police never questioned him about hacking her phone.

Goodman previously told the court Princess Diana gave him a book of royal directories while he was working at the now-defunct newspaper in 1992. However, this is the first time he has admitted to hacking the phones of members of the Royal family while working at the tabloid.

Goodman has not appeared in court since he was declared unfit to stand in March following a minor heart operation.