LONDON — The tricks of the trade of Britain's tabloid press came under scrutiny Thursday, after a newspaper reported that a tabloid owned by media mogul Rupert Murdoch had illegally hacked into the mobile phones of hundreds of celebrities and politicians.

But in the end, police said they would not reopen an investigation into the claims against Murdoch's News of the World, accused by The Guardian newspaper of paying private investigators to obtain voice mail messages, bank statements and other information about public figures, including Gwyneth Paltrow, George Michael and senior British politicians.

The News of the World's royal editor, Clive Goodman, was jailed in January 2007 for hacking into the phones of palace officials, and The Guardian claimed the practice was widespread at the newspaper at the time.

On Thursday morning, Paul Stephenson, London's police chief, announced that he had appointed a senior Scotland Yard officer to look into The Guardian's claims. But seven hours later, that officer, police Assistant Commissioner John Yates, announced that the allegations had been thoroughly examined during the Goodman case and "no further investigation is required."

Britain's chief prosecutor, Keir Starmer, then said he had ordered an urgent review of the evidence given by police to prosecutors in the Goodman case to be sure that "the appropriate actions" had been taken.

Starmer said he had "no reason to consider that there was anything inappropriate in the prosecutions that were undertaken in this case," and the Crown Prosecution Service declined to say whether new charges could be laid.

The Guardian reported that the News of the World — the country's most popular Sunday paper — paid private investigators to obtain private information about as many as 3,000 public figures, from late reality TV star Jade Goody to former Deputy Prime Minister John Prescott.

The News of the World is owned by News International Ltd., a subsidiary of Murdoch's News Corp., whose U.S. media outlets include Fox Television, the Wall Street Journal and the New York Post.

Citing anonymous senior police sources, The Guardian said journalists at the tabloid used private investigators to hack into private voice mail messages, using the information to "gain unlawful access to confidential personal data, including tax records, Social Security files, bank statements and itemized phone bills."

The Guardian wrote that the News of the World had paid more than $1.6 million in secret out-of-court settlements to three of the targets, including Gordon Taylor, chief executive of the Professional Footballers' Association.