Analysis: Met and News International
The most interesting fact to emerge from the Home Affairs Committee's questioning of Sir Paul Stephenson, the outgoing commissioner, was that 10 members of Scotland Yard's PR and communications staff formerly worked for News International.
Is that unusual, given the size of Rupert Murdoch's newspaper business in the UK? That is probably a question for the review of ethics and relations between police and the press.
But on Wednesday morning it was grist to the mill of the Met's critics who say, like the like the Home Affairs Committee, the force had no "real will" to take on the newspaper group amid "deliberate attempts" to thwart investigations.
Sir Paul Stephenson, in what was his final appearance before MPs, was defiant. He delivered a pithy soundbite, declaring he had not quit because he was pushed, but because it was the right thing to do as a leader.
But what MPs wanted to bottom out - and did not - was the exact business around Neil Wallis, the former News of the World executive who gave PR advice to the force before being arrested last week in the hacking probe.
The issue boils down to two key points.
The first question relates to how Mr Wallis was employed.
The second relates to who needed to know about that contract, and when, as the News of the World's hacking defence began to crumble.
Starting with who needed to know, the first the public heard of Mr Wallis's contract with the Met was in the hours after his arrest. Neither the home secretary nor prime minister had prior knowledge, we are told.
Sir Paul said to MPs on Tuesday he had no reason to tell the prime minister about Mr Wallis because, when he was employed in October 2009, he had not featured in the original hacking investigation.
But the question from critics is whether there came a point when the force should have said something about Mr Wallis, not least because the PM had seen his own PR chief, Andy Coulson, quit and be subsequently arrested.
Sir Paul said that he only knew "several weeks ago" that Mr Wallis was a potential suspect in Operation Weeting.
Twists and turns
But was there an attempt to tell Downing Street last autumn, after a critical article about the News of the World in the New York Times?
In committee, it initially sounded like the Met considered talking to Number 10 about Mr Wallis's PR contract - but were warned off.
But John Yates, who resigned as a Met Police assistant commissioner on Monday, subsequently told MPs he had offered to talk Number 10 through the processes detectives were following over hacking, rather than operational twists and turns.
That e-mail exchange has now been released.
On 10 September, Mr Yates e-mailed Ed Llewellyn, the prime minister's chief of staff, and said: "I am coming over to see the PM at 12.30 today [on national security matters]. I am very happy to have a conversation in the margins around the other matters that have caught my attention this week if you thought it would be useful."
Mr Llewelyn replied: "Assuming we are thinking of the same thing, I am sure you will understand that we will want to be able to be entirely clear, for your sake and ours, that we have not been in contact with you about this subject.
"So I don't think it would really be appropriate for the PM, or anyone else at No 10, to discuss this issue with you, and would be grateful if it were not raised please."
Scotland Yard's line is that there was never any discussion with Number 10 about Mr Wallis because top officers do not normally brief politicians on operational matters unless they really need to know.
What becomes clear from the e-mail exchange - and the differing accounts of Sir Paul and John Yates - is that the commissioner, as the strategic head of Britain's most important police force, left the details to his subordinate.
Which brings us to the unresolved business of how Mr Wallis was appointed. Sir Paul said he had been consulted prior to the appointment, but the decision was for others.
Dick Fedorcio, the Met's director of public affairs, got a grilling from the committee when he did not say who had recommended Mr Wallis as a consultant.
He went as far as denying it had been former News International chief executive and News of the World editor Rebekah Brooks.
The PR chief stressed he relied on John Yates to carry out due diligence on Mr Wallis prior to offering the contract.
Nicola Blackwood MP, a Conservative member of the committee, pressed him on this point, asking whether it had been appropriate given Mr Wallis and Mr Yates were friends.
Did that not put the police officer in a difficult position, she asked?
Mr Fedorcio said he trusted Mr Yates's judgement in carrying out "a form of due diligence".
He was, after all, one of the top police officers in the country.
But John Yates, who believes he is a victim of malicious press rumour rather than wrongdoing, said due diligence was not his job.
The MPs have sided with John Yates on this specific point. Although Dick Fedorcio was very much the undercard at the hearing, the MPs were scathing about his role.
"He [Mr Fedorcio] failed to answer when asked whether he knew that AC Yates was a friend of Mr Wallis," they said.
"He entirely inappropriately asked Mr Yates to sound out Mr Wallis although he knew that Mr Yates had recently looked at the hacking investigation of 2005-06; and he attempted to deflect all blame on to Mr Yates when he himself was responsible for letting the contract," he added.
The PR chief's role in the affairs had already been referred to the police watchdog.
Mr Yates maintained to the committee that he asked Mr Wallis, his friend and occasional companion at sporting events, to give one simple assurance: that his appointment would not lead to embarrassment later on.
The assurance came - but so did the embarrassment.
This affair has been disastrous for the careers of two of the UK's most important police officers - but the figure who comes out worst in the MPs' report has already left the force: former head of counter-terrorism, Andy Hayman.
He was nominally in charge of the 2006 hacking investigation - but the MPs say they do not know what he actually did.
They accuse him of being "lackadaisical" over his contacts with News International and they are scathing of how he landed a job at The Times (proprietor: R Murdoch) within months of leaving Scotland Yard.
The Met's former top officers are ruing the day they ever got chummy with News International.
But the really important issue is what will happen to the small number of lower-ranked operational cops now suspected of selling information.
On Tuesday John Yates confidently predicted they will be jailed for corruption.
He argued that weeding out the minority responsible for a problem does not taint an organisation. But the Metropolitan Police has been in a similar situation before.
Back in 1993, just one part of the force was responsible for the botched investigation into Stephen Lawrence's death.
The failings - and the force's collective failure to recognise and deal with them - led to the damning verdict of "institutional racism".
The reputational damage and collapse in public confidence was massive; the question is whether the Met can avoid the same fate again.