A Labour MP was put under surveillance by a private investigator working for the News of the World, it has been confirmed.
Lawyers for News Corporation said Tom Watson - who is an outspoken critic of Rupert Murdoch's media empire - had been placed under surveillance for five days in 2009.
In a letter to the Commons Culture, Media and Sport Committee, law firm Linklaters said three employees had been involved in commissioning private investigator Derek Webb to carry out the work.
The firm, which represents News Corp's management and standards committee (MSC), was responding after MPs submitted a further list of questions to James Murdoch following his last appearance before them last month.
The committee sought information over allegations that all its members were put under surveillance by News of the World journalists and by private investigators employed by the now defunct newspaper for between three and 10 days in 2009.
Linklaters said the MSC was currently looking into the matter and its inquiries were not yet complete. However, there was information that Mr Watson was under surveillance by Mr Webb between September 28 and October 2.
"The MSC's present understanding is that three employees were involved in commissioning this surveillance," Linklaters said.
"We do not think it appropriate to name the individuals involved given the ongoing police investigations. We have discussed this with the Metropolitan Police Service who share this view.
"The MSC has seen no information yet to suggest that any other member of the committee (or their family or friends) was under surveillance."
Mr Webb, a former police officer, has claimed the News of the World paid him to target more than 90 people over an eight-year period, including Prince William, former attorney general Lord Goldsmith and Harry Potter actor Daniel Radcliffe's parents.