A private investigator, hired by Rupert Murdoch's News of the World, carried out undercover surveillance of Prince William during the time when the newspaper was investigated for hacking his voicemail, reports claimed on Tuesday.

The BBC reported that private detective Derek Webb conducted the surveillance on the Prince while he was in Gloucestershire during the year 2006.

An ex-police officer, Webb also carried out similar surveillance works on other celebrities and high-profile individuals at that time. Included in this list are the Harry Potter actor Daniel Radcliffe's parents, Prince Harry's former girlfriend Chelsy Davy and the former attorney general Lord Goldsmith.

Basically I would write down what they were wearing at the time, what car they were in, who they met, the location they met, the times - the times were very important - and I would keep that, the investigator told BBC Newsnight.

Although the surveillance was not illegal, the manner and the scale at which it was conducted raised serious ethical questions regarding the function of the British newspaper.

News of the World, operating as the Sunday sister paper of The Sun, concentrated mainly on celebrity based news and populist news. In fact, the tabloid had garnered a lot of attention for exposing national or local celebrities.

It was in 2006 that phone hacking allegations engulfed the company. Murdoch was finally forced to shut down the newspaper after it became evident that their reporters eavesdropped on the mobile phone voice mail messages of a missing teenage girl who was later found murdered.

The BBC mentioned that this touched off a storm of public criticism that shook Murdoch's media empire and sent tremors through Britain's political, police and media establishments.

Although the Duke of Cambridge has been informed about the latest developments of being followed by the private eye, royal officials have declined to comment on it.