It is difficult to imagine a more damaging story for the News of the World than yesterday's revelation by The Guardian that it may have hacked the voicemail messages of murdered schoolgirl Milly Dowler.
It is alleged that Glenn Mulcaire, the News of the World's then full-time investigator, targeted Dowler's phone in the weeks after she disappeared in March 2002.
The Guardian reports evidence found in a collection of 11,000 pages of notes kept by Mulcaire. Milly's voicemail messages were reportedly deleted, because the mailbox became full, to allow more potential story leads to come in.
Under then editor Rebekah Wade (now Brooks) the News of the World campaigned on behalf of the family of murdered eight-year-old Sarah Payne for a change in the law to make the addresses of known paedophiles public knowledge.
It is breathtaking to think that at the same time that the Sarah's Law campaign was under way, an operative working for the News of the World may have committed a final indignity against Milly by invading her privacy and intercepting mobile phone voicemail messages as her body still lay undiscovered.
As The Guardian reports, there is evidence that the voicemails were used to produce at least one story.
It quotes a News of the World piece from 14 April 2002 which said a woman allegedly pretending to be Milly Dowler had applied for a job with a recruitment agency: "It is thought the hoaxer even gave the agency Milly's real mobile number … the agency used the number to contact Milly when a job vacancy arose and left a message on her voicemail … it was on March 27, six days after Milly went missing, that the employment agency appears to have phoned her mobile."
BBC business editor Robert Peston (who appears to be the chosen outlet for briefing from the highest level at News International) today reports that Brooks has no plans to resign from her current job as chief executive of News International.
But it is difficult to see how her position cannot be in jeopardy. The Dowler allegations are on a different scale of seriousness to the celebrity phone-hacking revelations which prompted Andy Coulson's two resignations (as editor, and then as Tory spokesman).
They are incredibly damaging for the News of the World - prompting as they have done front page coverage in today's Guardian, Telegraph, Independent, Daily Mail and Financial Times. Even sister title The Times published them in a side-bar on the front and across page three. They warranted a news-in-brief on page two of today's Sun and The Mirror, hitherto relatively quiet on the phone-hacking story, also ran the story as a page lead.
The News of the World faces the risk of a massive backlash from readers, and perhaps even advertisers too.
The huge frustration for current News of the World editor Colin Myler and his team is that almost no senior editorial figure working on the News of the World in 2002 is still there. As far as we know the culture of phone-hacking at the paper was wiped out after the jailing of Clive Goodman and Glenn Mulcaire and the resignation of Coulson in January 2007. And insiders would argue that the paper now goes further than others in keeping its nose clean.
Even Guardian editor Alan Rusbridger admitted, after picking up Newspaper of the Year at the British Press Awards, that he has no beef with the current News of the World staff.
But any current attempt to detoxify the News of the World brand will be stymied by allegations that there is so much muck on the hands of the paper's boss.