So, who did hack Milly Dowler's phone?

Scotland Yard is hunting for new evidence to confirm whether a senior journalist at the News Of The World deleted the murdered schoolgirl Milly Dowler's voicemails, thereby giving her parents false hope that she was still alive.

A revised timetable of what happened immediately after the 13-year-old disappeared in March 2003 has created uncertainty about key assumptions of the phone-hacking scandal. Yesterday, the Metropolitan Police ruled out the private investigator Glenn Mulcaire as the person who initially hacked into her mobile phone account. But The Independent understands that Surrey Police have evidence which points to a former senior newsdesk executive at the NOTW as the journalist who first accessed Milly's voicemails within 72 hours of her disappearance.

With the Sunday tabloid desperate to be the paper which found the teenager, its journalist is believed to have obtained her mobile number and Pin and deleted messages – so that new callers could leave messages which might reveal her location. The Independent has been told the identity of the journalist but cannot name him for legal reasons. He is already on police bail in connection with the phone-hacking scandal.

Last weekend, after the updated police timetable challenged the early involvement of Mulcaire – but crucially not his later involvement in hacking Milly's phone – The Guardian newspaper corrected its original story revealing the interception of the schoolgirl's voicemails to suggest that the NOTW was not responsible for deleting messages which led her mother to wrongly believe she was still alive.

That statement led to claims that News International may have been wrongly blamed, that the revulsion of its illegal practices may have been misplaced, and that both the closure of the NOTW and the Leveson Inquiry into press standards were unnecessary results. But the Dowler family's lawyer, Mark Lewis, described The Guardian's explanation as "a premature apology".

At the Leveson Inquiry yesterday, lawyers for the Met Police explained the impact of the new evidence which altered Mulcaire's role in the scandal. Neil Garnham, QC, said the moment Sally Dowler learnt that her daughter's phone messages had been deleted was before Mulcaire became involved in the story for the NOTW.

Mr Garnham said: "The visit by the Dowlers to the Bird's Eye building [where Mrs Dowler had called her daughter's phone] was on 24 March. Mr Mulcaire was not tasked in relation to the Dowler story until some time after that."

Stating it was "not yet possible to provide a comprehensive explanation" for what happened to Milly's voicemails, Mr Garnham said it was conceivable other News International journalists had deleted them, but he admitted that Scotland Yard held no evidence to support this. One explanation – that Milly's messages were "automatically" deleted after 72 hours – was described last night by Mr Lewis as "a complete red herring".