Detectives are investigating Rupert Murdoch over comments he made in an internal meeting with journalists from the Sun that were secretly recorded.

The Metropolitan police want access to the recording as part of the Operation Elveden inquiry into corrupt payments to public officials, assistant commissioner Cressida Dick said on Tuesday.

It is understood that one of the offences being investigated by the force is conspiracy to commit misconduct in public office.

Dick told MPs on the home affairs select committee: "We are seeking to obtain the tape of the meeting during which Rupert Murdoch appears to have been recorded. We will then assess the full contents of that tape."

She refused to be drawn on whether police had already obtained the full tape or whether they were seeking a court order for the media organisation to hand it over. "I am not prepared to go further," she told MPs.

The revelation comes as Murdoch was summoned to appear before the culture, media and sport select committee again over what he said in the March meeting recorded by News International journalists.

Exaro News, the website that published parts of the recording, said on Tuesday it was arranging to supply the evidence to Operation Elveden. Mark Watts, editor of Exaro News, said he was giving the police what had already been published on the website – three audio clips from the meeting.

Murdoch told the journalists that the culture of paying police officers for stories "existed at every newspaper in Fleet Street. Long since forgotten. But absolutely", and had existed long before Sun journalists had been arrested.

Murdoch also criticised the "incompetent" police investigation that has led to the arrest of so many of his staff.

In one clip broadcast by Channel 4 News, a journalist asks Murdoch: "I'm pretty confident that the working practices that I've seen here are ones that I've inherited, rather than instigated. Would you recognise that all this predates many of our involvement here?"

Murdoch replies: "We're talking about payments for news tips from cops. That's been going on a hundred years, absolutely. You didn't instigate it."

Dick told the committee relationships with News International and its management and standards committee had always been challenging. A memorandum of understanding for the "voluntary provision of documents" had been signed by the police and the standards committee – which eventually handed over more than 300,000 staff emails. But in recent months all requests by the police for new information were going through the courts, where police have to seek a production order for information from a media organisation.

"Since May of this year, voluntary co-operation has been significantly reduced," said Dick. "And all requests for new material are now supervised by the courts."

Asked about Murdoch's comments that the police investigation – which is likely to cost almost £40m by 2015 – was a disgrace and that the "cops are totally incompetent", Commander Neil Basu, who is running the linked Operations Elveden, Weeting and Tuleta, said he was not surprised by the media tycoon's comments as they were made in a meeting that was about providing "empathy for his staff".

Keith Vaz, chair of the home affairs select committee, challenged Dick on whether the inquiries – which have so far resulted in 126 arrests but led to only six convictions – could be described as incompetent.

Dick said: "I don't think it's a valid way of assessing success or otherwise, particularly at this stage – the number of people convicted." She said she was extremely satisfied the investigations had been very competent.

Basu told the committee that more arrests – probably numbering fewer than 10 – were likely in the coming weeks and months but the police were coming to the end of the arrest phase.

To date, 42 people have been charged, 56 are still on bail and 24 have been told no further action is being taken against them.

In a statement a spokesperson for News Corp said: "Mr Murdoch welcomes the opportunity to return to the select committee and answer their questions. He looks forward to clearing up any misconceptions as soon as possible."