Mea culpa that reaches right to the very top

News International's admission that it was responsible for the hacking of the phones of public figures ranging from a former member of the Cabinet to a Hollywood actress represents a seismic moment for the management of Britain's biggest newspaper publisher, reverberating all the way back to Rupert Murdoch.

The acceptance of liability on a grand scale has implications which stretch across the Atlantic to the heart of News Corporation. Why, Mr Murdoch will surely ask himself, didn't he take a personal grip of this situation before it reached such a pass?

At Dow Jones & Co, the publishers of Mr Murdoch's prized Wall Street Journal, the chief executive Les Hinton might ask himself why, as executive chairman of News International (NI) throughout the period in question, he presided over an organisation responsible for such behaviour, but told MPs that "there was never any evidence delivered to me" suggesting that phone hacking went beyond Clive Goodman, the royal editor of the News of the World jailed in January 2007.

It is a difficult time, too, for James Murdoch, whose promotion and relocation to New York last month looks like a timely escape from the firing line. Three years ago, James sanctioned a £1m payment to phone hacking victim Gordon Taylor, head of the Professional Footballers' Association, and he is open to criticism that he – newly installed as head of News Corp in Europe & Asia – failed to appreciate the seriousness of the scandal.

The chief executive of NI, Rebekah Brooks, is also damaged by yesterday's admission. She not only has a responsibility for the NOTW, but edited the newspaper between 2000 and 2003. She denies knowing about phone-hacking when it was taking place. Yesterday's statement from NI was pointedly headed "2004-2006", a period throughout which Andy Coulson edited the paper. Coulson lost his job, then had to quit as director of communications at Downing Street, and has told detectives that he was unaware of a hacking culture under his editorship. The confirmation of eight further cases – with the certainty of more to come – threatens to expose other members of his newsroom and undermine his claim to MPs that Goodman was a "rogue case".

The current editor of the NOTW, Colin Myler, must be embarrassed by yesterday's statement. In the wake of Goodman's conviction, Myler was put in charge of an investigation into the extent of hacking at the paper. Two years later he told MPs that he had studied 2,500 emails, yet had uncovered "no evidence" that required further action. But in some cases, courts have heard allegations that other NOTW journalists were party to the hacking process.

Last week, two NOTW figures, the former head of the newsroom Ian Edmondson (who has been sacked by NI) and the current chief reporter, Neville Thurlbeck, were arrested on suspicion of conspiring to access the voicemails of public figures.

In the civil case brought by football pundit Andy Gray, in which NI has admitted liability, a court was told that documents marked by Mulcaire for "Greg" referred to Greg Miskiw, a former journalist at the NOTW.

Yesterday Ms Wade emailed staff expressing regret for the company's behaviour. "It is now apparent that our previous inquiries failed to uncover important evidence and we acknowledge our actions then were not sufficiently robust," said the statement.

Emerging unscathed from this is Will Lewis, the former Daily Telegraph editor who joined NI as group general manager last autumn and has spent months preparing the strategy for yesterday's grand mea culpa.

NI hopes its offer of a compensation scheme, headed by an ex-High Court judge, will mean that Mr Justice Vos, who next Friday oversees a case management conference of the 24 suits against it, will appreciate its efforts to hasten the legal process. He is not the only person the company needs to win round.

Who should be worried at News International - and why

James Murdoch

As executive chairman of News International, he personally authorised a £700,000 pay-off to Gordon Taylor, head of the Professional Footballers' Association, after his messages were hacked.

Les Hinton

Chief executive of News International at the time covered by the apology. He told MPs: "There was never firm evidence provided that implicated anybody else other than Clive. It just did not happen."

Colin Myler

Current editor of the News of the World, who was in charge of the internal investigation. He told MPs there was "no evidence" anyone else had been involved, having trawled "thousands" of emails.

Andy Coulson

Former News of the World editor who said under oath: "I don't accept there was a culture of phone-hacking at the News of the World. There was a very unfortunate case involving Clive Goodman."

Rebekah Brooks

Now CEO of News International, she is a close friend of Andy Coulson and was his predecessor as editor at the News of the World. Responsible for handling the fallout from the hacking affair.