The star of the marathon committee session on phone hacking was undoubtedly Andy Hayman, the then top copper who was in charge of the first inquiry that led nowhere.

He must be given his own sitcom, a blend of Life On Mars and Minder, starring Hayman as Del Boy. One of the MPs called him "a dodgy geezer" to his face. Put it this way: I wouldn't let him sell me a cheap Rolex, if I wanted to know the time.

His evidence followed other high-ranked plods. As usual John Yates was given a toasting by the committee (he must be a masochist; nothing stops him coming back for more). The chairman, Keith Vaz, told him that his evidence had been "unconvincing", and he could expect to be summoned again. We half-expected him to say: "Ooh, yes, please!"

But to the committee, he was George Washington compared with Mr Hayman. I've seen a few incredulous MPs in my time, but nothing like this. Through most of Mr Hayman's evidence they were either rolling with laughter, or favouring him with a cold, sardonic glare. Or both.

Mr Vaz asked about the fact that he had taken a job as a columnist with News International, the very firm he had been investigating. "That is a private matter for me and the Times," said Hayman primly, to startled surprise.

They asked about his private life. Was it true he'd been hacked over that? "'Aven't got a clue," he replied. It turned out this was one of his catchphrases, along with "dunno", "can't remember", "can't recall" and "that was four or five years ago!"

"All this sounds more like Clouseau than Columbo," said Vaz, in what may have been a microwaved soundbite.

Mark Reckless pointed out that both he and the former DPP were now working for News International. "Do you wonder how that looks to the public?"

Hayman: "It could look bad."

Vaz: "We all think it looks bad."

Julian Huppert, a Lib Dem, said that some of what he said was "quite incredible". Mr Hayman snapped into "who, me? I swear on my baby's life …" mode.

"OK," he said, "beat me up for being upfront and honest!"

The Tory Michael Ellis, his voice swooping up and down with astonishment, said: "You made a judgment call to accept hospitality from the people you were investigating?"

Hayman: "Yeah." (Mocking laughter) He added: "Not having the dinner would have been potentially more suspicious than to have it." (Louder laughter.)

"I dunno why you're laughing … we would never, ever have a dinner that would compromise the investigation."

(I wonder what would have happened if he had troughed with a top stolen car dealer. "I do hope you find the lobster Newburg and foie gras to your taste, Basher.")

Nicola Blackwood, a Tory, looked faint. "I feel I've fallen through a rabbit hole," she breathed.

Stephen McCabe, Labour, wanted to know why Hayman had ridiculed John Prescott when he said his phone had been hacked. Vaz: "You said he was ranting and there was no evidence. You said that if he was right, you would eat your words."

Mr Vaz asked if he should pass him a piece of paper, and for a moment we thought he was going to force Hayman, physically, to eat his words.

Lorraine Fullbrook, another Tory, asked outright if he had ever accepted money from NI.

You would have thought she'd accused him of being a predatory paedophile, not someone who had conducted a hopelessly inadequate inquiry into a firm which had wined and dined him, and then given him a well-paid job.

"Good god!" he exploded. "Absolutely not, I can't believe you suggested that! That is a real attack on my integrity!"

Keith Vaz concluded: "Normally I would sum up the evidence, but on this occasion, it speaks for itself." And he didn't mean it in a kind way.

• This article was amended on 13 July 2011. The original referred to the Tory MP Mark Ellis. This name has been corrected.