LONDON (AP) - Newly disclosed evidence in Britain's tabloid phone hacking scandal confirmed Wednesday that an outspoken critic of Rupert Murdoch was put under surveillance by his now defunct tabloid the News of The World.
Lawmaker Tom Watson, who has led efforts to expose the extent of malpractice in Britain's newspaper industry, was followed for five days in 2009 by private investigator Derek Webb, a former police officer.
Law firm Linklaters, which represents the management and standards committee of Murdoch's News Corp., said in a letter sent to Parliament's Culture, Media and Sport committee - which is investigating phone hacking - that three employees of the tabloid were responsible for commissioning Webb to spy on the Labour Party legislator.
"We do not think it appropriate to name the individuals involved given the ongoing police investigations," Linklaters said in its letter.
Lawyer Mark Lewis, who was also spied on by the newspaper, had previously said that he had seen evidence that Watson, a former government minister, had been under surveillance.
The admission "is no longer surprising, though I am intrigued to know the names of the three executives who commissioned the covert surveillance," Watson told The Associated Press in a text message.
Linklaters also acknowledged that internal inquiries showed that the ex-chief executive of News International, Rebekah Brooks, had authorized a settlement in 2010 with celebrity publicist Max Clifford over the hacking of his phone.
"Mrs. Brooks was authorized to conclude this agreement by virtue of her position as chief executive of News International. The MSC (News Corp. Management and Standards Committee) has seen no information to suggest that this agreement was discussed by the boards of News Group Newspapers, News International or News Corporation," the letter said.
Watson said that disclosure threw up more questions over the extent to which the tabloid's executives were aware of malpractice. "Was she aware that others were involved in wrongdoing and if so, why didn't she immediately act," he told the AP.
Brooks, a former News of The World editor, was arrested by police in July and later released on bail.
Parliament's culture committee had asked Linklaters whether all 11 of its members, including Watson, had been put under surveillance.
News Corp. had "no information yet to suggest that any other member of the committee (or their family or friends) was under surveillance," the law firm said in the letter, dated Dec. 1.
In another letter, Neville Thurlbeck, a former chief reporter at the News of The World - who was arrested on suspicion of phone hacking and later released - told the committee he had repeatedly offered executives what he says is evidence that several members of staff were aware of the use of hacking at the tabloid.
For many months, executives maintained that phone hacking was the work of a single rogue reporter. Thurlbeck insists that claim was false, and that he had urged two key executives to review his contradictory evidence to before they appeared before lawmakers and laid the blame on a lone employee.
"They were in possession of all this knowledge and they failed to disclose it to the committee," he wrote in his letter to the panel dated Nov. 29.
Only two people have been jailed for phone hacking, both in 2007 - News of the World reporter Clive Goodman and Glenn Mulcaire, a private investigator convicted over hacking into the voicemail messages of royal staff while working for the tabloid.
The release of the documents came as British police arrested an 18th suspect in their investigation, named by media including Sky News - which is 39 percent owned by Murdoch's News Corp. - as Mulcaire.
London's Metropolitan Police said a 41-year-old man was held Wednesday on suspicion of conspiring to intercept voice mail messages and pervert the course of justice. It declined to release the man's name.
Mulcaire's lawyer, Sarah Webb, declined to comment.
Police said later the man had been released on police bail until late March, pending further investigations. "It would be inappropriate to discuss any further details at this time," police said in a statement.
London police have identified 5,795 potential phone-hacking victims in material collected from Mulcaire, the private investigator at the center of the scandal. A British media practices inquiry has seen the names of at least 28 News International employees in notes kept by Mulcaire - and five journalists alone had asked Mulcaire to carry out 2,266 tasks.
More than a dozen News of the World journalists, including former editor Andy Coulson, have been arrested in the scandal. Two top London police officers and several senior Murdoch executives also have resigned in the scandal, which has led to multiple investigations and damaged Murdoch's global media empire.
Coulson, who resigned as Prime Minister David Cameron's media adviser in January when he became embroiled in the investigation, is suing News of the World's publisher for stopping the payment of his legal fees in the hacking case.
Coulson left the paper in 2007, but his lawyer James Laddie asked Justice Michael Alan Supperstone at London's High Court to rule that News Group Newspapers must pay Coulson's costs in defending himself from allegations of criminality during his tenure as editor.
Christopher Jeans, representing News Group Newspaper, argued that a clause in Coulson's severance agreement covers the "occupational hazards of being an editor" but "in no way covers personal criminal wrongdoing."
Supperstone will rule at a later date.