The British newspaper arm of Rupert Murdoch's News Corp said on Monday its staff had ordered surveillance to be carried out on two lawyers representing victims suing the media group over the phone-hacking scandal which has engulfed the company.
News International, the UK newspaper arm of News Corp, admitted that the action, the latest in a string of embarrassing and damaging revelations about illegal eavesdropping on phone messages, was inappropriate.
It also adds to growing pressure on Murdoch's son James, the chairman of News International who is due to face British lawmakers for a second time on Thursday as part of a probe to find out how much he knew about the hacking scandal.
Private detective Derek Webb said he had been hired by the now defunct News of the World paper to spy on lawyers Mark Lewis and Charlotte Harris, who represent some of the most high-profile victims, the BBC reported.
The BBC that he had covertly followed them and filmed Lewis's family on a shopping in early 2010. The broadcaster said the surveillance was part of efforts to suggest Lewis was having an affair with Harris and was sharing confidential information with her.
Webb, a former policeman for 15 years, said in an interview with the BBC that the investigation of the two lawyers only stopped when News of the World closed.
News International closed the News of the World in July amid public disgust at disclosures its journalists had hacked into the phone of schoolgirl Milly Dowler who was abducted and murdered in 2002. Lewis represents the Dowler family.
News International's enquiries have led the company to believe that Mark Lewis and Charlotte Harris were subject to surveillance, a News International spokeswoman said.
While surveillance is not illegal, it was clearly deeply inappropriate in these circumstances. This action was not condoned by any current executive at the company.
Until this year, News International bosses said they were unaware of the extent of hacking at the paper, arguing it had involved only one rogue reporter who was jailed along with a private detective in 2007.
Evidence has emerged from the parliamentary inquiry that senior executives were told there was a wider problem as far back as 2008.
The scandal has broadened to include allegations of bribing police officers. Top British police officials have resigned and Prime Minister David Cameron was embarrassed for having hired a former News of the World editor as his media advisor.
The latest revelations will fuel criticism that the company and James Murdoch, the presumed heir to the media empire, had failed to get a grip on the scandal when they had been told of the scale of the problem.
Speaking on the BBC's Newsnight programme Mark Lewis described the investigation of his family as horrific and said it was an attempt to smear his private life and cause personal intimidation.
People shouldn't have been looking at me to see what I did in my private life. Nothing about my private life could possibly have affected anything that I was doing at work.
Tom Watson, a member of powerful committee investigating the scandal who has played a prominent role in uncovering information, said the two Murdochs should take the blame.
This shows a company rotten to the core. Ultimately you can delegate power but not responsibility and no one on the board of News Corp has taken responsibility for what's gone on this year and in previous years, he told ITV News.
It's time for James and Rupert Murdoch to carry the can for what's gone on their watch.
(Editing by Peter Graff)