Britain’s top-selling Sunday tabloid vowed to take the “strongest possible action” if it is proven that its journalists hacked the phone of a missing teenager who was later found murdered.

News International chief Rebekah Brooks, who was editor of the newspaper at the time of schoolgirl Milly Dowler’s disappearance in 2002, told staff that the allegations were “sickening” and “almost too horrific to believe”.

The following are the key events of the phone-hacking scandal in chronological order:

2006

August 8 - Detectives arrest the News of the World’s royal editor Clive Goodman and private investigator Glenn Mulcaire over allegations that they hacked into the mobile phones of members of the royal household.

2007

January 26 – Mr Goodman is jailed for four months and Mr Mulcaire for six months after they admit intercepting voicemail messages on royal aides’ phones, including some left by Prince William. News of the World editor Andy Coulson resigns, saying he “deeply regrets” what happened and takes “ultimate responsibility” for it.

May 18 – The Press Complaints Commission says in a report that it is satisfied no-one else at the News of the World knew Mr Goodman and Mr Mulcaire were tapping phone messages.

May 31 – Then-opposition leader David Cameron announces that Mr Coulson has been appointed as the Conservative Party’s director of communications and planning.

2009

July 9 – The Guardian newspaper claims that News Group Newspapers, which publishes the News of the World, has paid out more than £1 million to settle cases which threatened to reveal evidence of its journalists’ alleged involvement in phone-hacking. Scotland Yard says it will not be carrying out a new investigation into the allegations, but the Crown Prosecution Service announces a review of material provided by the police in 2006.

July 21 – Mr Coulson tells MPs on the Culture, Media and Sport Committee that things went “badly wrong” under his editorship of the News of the World, but insists he knew nothing about alleged phone-hacking.

November 9 – The Press Complaints Commission says in a second report that it has seen no new evidence to suggest anyone at the News of the World other than Mr Goodman and Mr Mulcaire hacked phone messages, or that the paper’s executives knew what the pair were doing.

2010

February 24 – A Culture, Media and Sport Committee report finds no evidence that Mr Coulson knew phone-hacking was taking place at the News of the World, but says it is “inconceivable” that no-one apart from Goodman was aware of it.

May 11 – Mr Coulson becomes head of the new coalition Government’s media operation after Mr Cameron enters 10 Downing Street as Prime Minister.

September 5 – The New York Times publishes a long article which claims Mr Coulson knew his staff were carrying out illegal phone hacking. The story also raises questions about how vigorously Scotland Yard pursued the case.

2011

January 21 – Mr Coulson announces he is standing down as Downing Street communications chief, saying the drip-drip of claims about illegal eavesdropping under his editorship was making his job impossible.

January 26 – Scotland Yard launches a fresh inquiry - Operation Weeting - into the phone-hacking controversy after receiving “significant new information” from the News of the World’s publisher, News International. Meanwhile, the paper sacks its assistant editor (news), Ian Edmondson, after he is linked to the scandal in documents relating to legal action by actress Sienna Miller lodged at the High Court.

April 5 - Scotland Yard detectives arrest Edmondson and the News of the World’s chief reporter, Neville Thurlbeck, on suspicion of conspiring to intercept communications and unlawfully intercepting voicemail messages. They are bailed.

April 8 – News International admits liability and apologises “unreservedly” to a number of public figures.

April 14 – Senior reporter James Weatherup becomes the third journalist associated with the Sunday tabloid to be questioned by detectives as part of the new probe.

June 21 – Football pundit Andy Gray accepts £20,000 in damages after his voicemail was intercepted by the News of the World. The newspaper reached a similar agreement with actress Sienna Miller, who was paid £100,000.

July 4 – Claims emerge that the mobile phone of murdered schoolgirl Dowler was hacked after she had gone missing. Her family’s solicitor said it offered her parents Bob and Sally false hope that she was still alive.

July 5 – News International CEO Rebekah Brooks says she is “appalled and shocked” that the teenager’s phone was hacked. The PM calls it a “truly dreadful act”.

Sign up to our free newsletters

Get the best updates straight to your inbox:
Please select at least one mailing list.

You can unsubscribe at any time by clicking the link in the footer of our emails. We use Mailchimp as our marketing platform. By subscribing, you acknowledge that your information will be transferred to Mailchimp for processing.