LONDON — As Rupert Murdoch’s newspaper empire on Saturday published full-page ads in every national newspaper in Britain under the words “We are sorry,” the government of Prime Minister David Cameron released information documenting the prime minister’s close ties to Murdoch company executives that continued even as the phone-hacking scandal grew.

The apology by Mr. Murdoch’s News Corporation was a U-turn from his previously defiant handling of the crisis. The banner headline in Saturday’s editions of The Times of London read “Day of Atonement,” and it was all the more striking for the fact that it ran in the 226-year-old newspaper that is the flagship of the print empire that Mr. Murdoch has assembled in Britain over the past 40 years.

At the end of a week that rocked the interwoven worlds of the press, politicians and the police in Britain, and spread across the Atlantic with the opening of an F.B.I. investigation into allegations of associated abuses in the United States, penitence was the buzzword far beyond the London headquarters of Mr. Murdoch’s British-based newspaper subsidiary, News International.

The crisis seemed far from over for Mr. Murdoch, as the scandal that began over illegal phone hacking by one of his newspapers, The News of the World, now defunct, widened to include a second newspaper in his stable, The Sunday Times, officials said Saturday.