LONDON (AP) — The press likes to cast itself as society's guardian. On Monday, the judge leading the investigation into Britain's deepening phone hacking scandal vowed to find an answer to the question: Who guards the guardians?

For years, the British media's answer has been that it mainly looks after itself. But following explosive allegations of pervasive criminality at Rupert Murdoch's News of the World tabloid, Lord Justice Brian Leveson suggested it was time for a change.

"Guarding the guardians is not an optional add-on," he said.

Britain's phone hacking inquiry was set up by Prime Minister David Cameron shortly after the scandal boiled over in July, pulling the lid off illegal spying at the nation's best-selling Sunday newspaper and exposing police corruption.

It's one of several investigations spurred by public anger over unethical practices at the now defunct paper. The long-running scandal has threatened Murdoch's global media empire, which includes the Wall Street Journal and dozens of other properties.

Parallel inquiries launched by police, prosecutors and parliamentarians have called Murdoch to Britain for dramatic testimony before lawmakers, led to more than a dozen arrests and the resignation of several top-ranking Murdoch executives. The resignations included The Wall Street Journal publisher Les Hinton, and Rebekah Brooks, who was at the helm of News of the World's publisher, News International.

The first part of Leveson's inquiry seeks to go beyond assigning blame to individual journalists or newspapers to evaluate the media's wider role. Among the questions on his agenda: Is the press above the law? Is it too close to police and politicians?

Although the News of the World has few defenders, editors and broadcast bosses have publicly voiced concern that recommendations from any inquiry could make Britain's press less aggressive — and less free. Few if any want more government regulation — especially since Britain's press already labors under strict libel laws and contentious new privacy rules.

While inquiry counsel Robert Jay said that the importance of a free press was "almost self-evident," he warned that the media may not necessarily like the solutions the inquiry finds for tricky ethical issues.

"These solutions will not necessarily have been the solutions which the press themselves would have devised," he said.

Leveson said he hoped to have the first part of his inquiry wrapped up by the end of 2012.

He's expected to recommend either scrapping or radically reforming the Press Complaints Commission, the self-regulatory body whose failure to get to grips with the hacking scandal has been roundly criticized. The scope of his inquiry's recommendations will hinge in part on whether illegal behavior is found to have been limited largely to the News of the World or whether it was practiced more widely.

There seemed to be plenty of evidence at Monday's hearing that shady practices were widespread.

Jay told the inquiry — whose proceedings were broadcast live over the Internet — that it appeared that illegal interception of voicemails went beyond the News of the World. He said that the inquiry had seen the names of no fewer than 28 News International employees in the notes kept by Glenn Mulcaire, the private investigator which the News of the World paid to illegally eavesdrop on its victims.

The words "The Sun" — a possible reference to the News of the World's sister-title — also cropped up in Mulcaire's notes, Jay said. So, too, did a name linked to the Daily Mirror, the Sun's left-wing rival, which is published by Trinity Mirror PLC.

Jay said that the evidence on phone hacking pointed to what he described as "at the very least, a thriving cottage industry."

The inquiry was briefly disrupted when David Sherborne, a lawyer for phone hacking victims, said that a Trojan, or data-stealing virus, had been found on his computer — raising the possibly that he was being hacked.

The otherwise cool and clinical Leveson briefly seemed speechless.

"I'm not often thrown, but Mr. Sherborne has managed to do that," he said. Sherborne later said the problem was being dealt with.

Sherborne was one of several dozen lawyers and journalists packed into a room at London's neo-gothic Royal Courts of Justice, with more in a spillover tent pitched into a nearby courtyard.

A handful of members of the public came to watch the proceedings as well — among them Bob Dowler, whose daughter Milly had her phone hacked by the News of the World at the height of the media frenzy over her disappearance in 2002. Although other victims of phone hacking were better known, the notion that the paper had violated the privacy of a missing child in the search for scoops sent a wave of outrage across the country.

Also at the hearing was Katriona Ormiston, a 21-year-old journalism student, who said she was there to see media history being made.

"Obviously it's got quite a big impact on the future," she said.

Meanwhile, allegations of shady dealings at News International continued to rumble on Monday. Roy Greenslade, a professor of journalism who blogs for the Guardian newspaper, said News International had ordered surveillance of a dozen different lawmakers investigating the company's illegal behavior.

News International didn't immediately return an email seeking comment, but the company has acknowledged previously spying on its critics in what one lawyer described as a "mafia-like" intimidation campaign.

On the Net:

■The Leveson Inquiry: http://www.levesoninquiry.org.uk/

■Raphael G. Satter can be reached at: http://www.twitter.com/razhael

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