Members of the public and journalists lined up hours ahead of time in hope of a spot in the small committee room, which holds about 40 people. More will be able to watch in an overspill room, and Britain's TV news channels are anticipating high ratings for the appearance.
Cameron cut short a visit to Africa and is expected to return to Britain for an emergency session Wednesday of Parliament on the scandal.
A former News of the World reporter, Sean Hoare, who helped blow the whistle on the scandal, was found dead Monday in his home. Police said the death was "unexplained" but is not being treated as suspicious. A post-mortem was being conducted Tuesday. Hoare was in his late forties.
Brooks' spokesman, David Wilson, said police had been handed a bag containing a laptop and papers that belong to her husband, former racehorse trainer Charlie Brooks. Wilson said the bag did not contain anything related to the phone hacking scandal and he expected police to return it soon.
The bag was found dumped in an underground parking lot near the couple's home on Monday, but it was unclear how exactly it got there. Wilson said Tuesday that a friend of Charlie Brooks had meant to drop the bag off, but he would say only he left it in the "wrong place."
In New York, News Corp. appointed commercial lawyer Anthony Grabiner to run its Management and Standards Committee, which will deal with the scandal. But News Corp. board member Thomas Perkins told The Associated Press that the 80-year-old Murdoch has the full support of the company's board of directors, and it was not considering elevating Chief Operating Officer Chase Carey to replace Murdoch as CEO of News Corp.
News Corp.'s widely traded Class A shares fell 68 cents to $14.97 Monday — down 17 percent since the scandal reignited on July 4.
Britain's Independent Police Complaints Commission also is looking into the phone hacking and police bribery claims, including one that Yates inappropriately helped get a job for the daughter of Wallis. Wallis has been arrested on suspicion of conspiring to intercept communications.
London police also confirmed that they once employed a second former News of the World employee besides Wallis. Alex Marunchak had been employed as a Ukrainian language interpreter with access to highly sensitive police information between 1980 and 2000, the Metropolitan Police said.
The police force said it recognized "that this may cause concern and that some professions may be incompatible with the role of an interpreter," adding that the matter will be looked into.
Meanwhile, Internet hackers took aim at Murdoch late Monday, defacing the sites of his other U.K. tabloid, The Sun, and shutting down website of The Times of London. Visitors to The Sun website were redirected to a page featuring a story saying Murdoch's dead body had been found in his garden.
Internet hacking collective Lulz Security took responsibility for that hacking attack via Twitter, calling it a successful part of "Murdoch Meltdown Monday."
Lulz Security, which has previously claimed hacks on major entertainment companies, FBI partner organizations and the CIA, hinted that more was yet to come, saying "This is only the beginning."
It later took credit for shutting down News International's corporate website. Another hacking collective known as Anonymous claimed the cyberattack on The Times' website.