Scotland Yard will "fully assess" the contents of a tape recording of comments apparently made by Rupert Murdoch in a meeting with News International journalists, a senior officer said today.
Murdoch has also been recalled to face MPs on the Commons' Culture, Media and Sport Select Committee following the emergence of the recordings.
Assistant Commissioner Cressida Dick told MPs on the Home Affairs Select Committee that the force is trying to get a copy of the clip of Murdoch speaking to members of staff from the Sun in March.
In the recording, obtained by the investigative website Exaro, a voice alleged to be Murdoch's says: "We're talking about payments for news tips from cops: that's been going on a hundred years. You didn't instigate it."
He is also claimed to have said that the company had started telling the Metropolitan Police to get court orders to obtain information, branded the force "totally incompetent" and said that their inquiries were "unbelievably slow".
Commander Neil Basu, who gave evidence to the Home Affairs Select Committee alongside Dick today, said he was "not surprised" to hear the criticism.
Dick hit back by saying the investigations were "progressing extremely well".
She said the force is currently trying to get a copy of the tape of Murdoch's comments, and added: "We will assess the full contents of that tape."
Earlier today, Exaro said it would be handing over all evidence it had, including two audio clips from the meeting, to the police but added that there was nothing that would come to light that had not already been published.
Basu revealed that police now believe that there could be up to 5,500 victims of phone hacking.
He is leading Scotland Yard's probes into claims of phone hacking, allegations of corrupt payments to public officials and computer hacking and other privacy breaches.
It is estimated that the inquiries will cost £38.8 million up to April 2015.
Basu told the committee that so far 3,500 alleged victims have been contacted under Operation Weeting, the phone hacking probe.
He said that 419 alleged victims have been identified as part of Operation Elveden, the payments probe, of whom 213 have been informed.
There are 154 allegations under Operation Tuleta, the inquiry into claims of computer hacking and other privacy breaches, involving 135 potential victims, all of whom have been contacted.
No date has been set for Murdoch's reappearance in front of the CMS committee but it is not expected before the autumn.