Rupert Murdoch has rowed back from claims that the investigation into phone hacking and corruption is "totally incompetent" but said Scotland Yard's probe appears "excessive" and has "gone on too long".
In a letter responding to demands from MPs that the media magnate explain comments he made about police at a staff meeting, he conceded using the "wrong adjectives" to describe his frustration at events over the last two years.
But the News Corp boss also questioned whether officers had "approached these matters with an appropriate sense of proportion" and said it would be unfair to suggest his company had impeded the Metropolitan Police's inquiries.
Mr Murdoch was apparently recorded describing the treatment of journalists who had been arrested as a "disgrace" during a meeting in March and saying that police had been told to obtain court orders to get information, rather than the company offering up material as it had done previously.
Home Affairs Select Committee chairman Keith Vaz wrote to Mr Murdoch asking him to comment on the secret recording.
In a reply released today, Mr Murdoch said: "I accept that I used the wrong adjectives to voice my frustration over the course of the police investigation.
"But I had been hearing for months about pre-dawn raids undertaken by as many as 14 police officers, and that some employees and their families were left in limbo for as much as a year and a half between arrest and charging decisions."
He added: "I have no basis to question the competence of the police and I and our newspapers respect the work that they do every day to protect the public.
"But I do question whether, over the last two years, the police have approached these matters with an appropriate sense of proportion, and with regard for the human cost of delay."
The Metropolitan Police's assistant commissioner Cressida Dick has told the committee that since May "voluntary co-operation (with News UK) has been significantly reduced and all requests for new material are now supervised by the courts".
Mr Murdoch said he did not take issues with the comment "as far as it goes" but insisted the company was not only producing information when required by the courts.
The letter sets out how the company disclosed 500,000 documents after 185,000 man hours at a cost of more than £65 million.
He said: "I am in no position to judge the competence of the investigation and should never have done so.
"My own lay view is that it has been more than thorough, indeed it has in some respects appeared to be excessive.
"I cannot endorse the judgment that the investigation has 'progressed' very well, not when some of our employees were arrested early in the investigation in 2012 and they and their families are still in limbo awaiting charging decisions.
"I appreciate that the decision to charge is for the Crown and that AC Dick has far more knowledge than I about the progress of the investigation.
"That said, my personal view is that this has gone on too long."
In the secret tape, which emerged earlier this month, Mr Murdoch is heard railing at the way the police behaved.
"Still, I mean, it's a disgrace. Here we are, two years later, and the cops are totally incompetent," he said.
"The idea that the cops then started coming after you, kick you out of bed, and your families, at six in the morning, is unbelievable.
"But why are the police behaving in this way? It's the biggest inquiry ever, over next to nothing.
"And now they're arresting their own, who never even took money. They're going to put all newspapers out of business."
When one of the journalists present questioned why so much material had been handed over to the police by News Corp's management and standards committee (MSC), Mr Murdoch indicated that he believed they had gone too far.
"Because - it was a mistake, I think. But, in that atmosphere, at that time, we said, 'Look, we are an open book, we will show you everything'. And the lawyers just got rich going through millions of emails," he said.
He added: "All I can say is, for the last several months, we have told, the MSC has told, and (name withheld), who's a terrific lawyer, has told the police, has said 'No, no, no - get a court order. Deal with that'."
In a second letter to the chairman of the Commons Culture, Media and Sport Committee, John Whittingdale, obtained by Channel 4 News, Mr Murdoch said that, at the meeting with staff, he had been confronted first-hand with the human cost of News Corp's decision to co-operate with the authorities.
"Even without a reliable transcript before me, I am sure I made overly emotional comments about the MPS (Metropolitan Police Service) at the March meeting. But the frustration that drove those comments was real, and rooted in the events that have taken place after I appeared before you," he wrote.
He added: "I do not doubt the police's professionalism but, from my layman's perspective, the police approach to these matters since I met with you has in some respects appeared to be disproportionate.
"I should not have spoken disrespectfully of the police. We all owe a great debt to the MPS for their work each day to protect the public. Still, I share my employees' frustration with the length of this process."
Mr Murdoch also insisted the reports that he "knew about let alone tolerated payments to police" were "completely false".
Labour MP Tom Watson, who has closely followed the case, said the letters appeared to be a "damage limitation exercise" written by one of the highly paid lawyers he had been so contemptuous of in private.
"It is very difficult to know what the real Rupert Murdoch is up to," he told Channel 4 News.
"He says one thing in public and does something else in private and then the lawyers get involved and he contradicts himself again. It is a total mess."