NOTW editor Brooks ordered searches from investigator

(Rex)

Rebekah Brooks, the chief executive of Rupert Murdoch's News International, personally commissioned searches by one of the private investigators used by the News of the World (NOTW) to trace the family of the murdered Surrey schoolgirl Milly Dowler.

Ms Brooks, while editor of NOTW, used Steve Whittamore – a private detective who provided the paper with the Dowlers' ex-directory home phone number – to "convert" a mobile phone number to find its registered owner. The Information Commissioner's Office (ICO), which successfully prosecuted Whittamore for breaches of the Data Protection Act in 2005, said last night it would have been illegal to obtain the mobile conversion if the details had been "blagged" from a phone company.

Ms Brooks, who said yesterday she was "shocked and appalled" at the latest hacking claims, admitted requesting the information, but she said it could be obtained by "legitimate means". She faced demands to quit last night.

News International is battling a political and commercial firestorm over the disclosure that its best-selling paper interfered with the police investigation into Milly's disappearance in March 2002 by hacking into her mobile phone and deleting messages. An emergency three-hour debate is to be held in the House of Commons today. David Cameron described the hacking as ""truly dreadful act".

The Labour leader Ed Miliband said that Mrs Brooks should "consider her conscience and consider her position".

Police confirmed there was evidence Glenn Mulcaire, the NOTW's private investigator who is accused of hacking Milly's phone, targeted the families of Holly Wells and Jessica Chapman, who were murdered in Soham in 2002.

Ms Brooks yesterday told News International staff it was "inconceivable" that she knew of or sanctioned the hacking of Milly's mobile phone. She wrote: "I am sickened that these events are alleged to have happened. Not just because I was editor of the News of the World at the time, but if the accusations are true, the devastating effect on Milly Dowler's family is unforgivable."

No evidence has been presented that Ms Brooks was aware of Mulcaire's activities surrounding Milly's disappearance. News International last night failed to comment on Ms Brooks' requests to Whittamore. Simon Greenberg, a company spokesman, said Ms Brooks would not be stepping down over the hacking of Milly's phone.