During a 10-minute delay to the start of the hearing, the sound of laughter could clearly be heard from inside the committee room by those waiting in the corridor outside. The chair of the public accounts committee, Margaret Hodge, later offered a partial explanation. “We were having some trouble making head or tail of the accounts,” she said.

She was not alone. Last week, the National Audit Office issued a rare “adverse opinion” on the financial affairs of the Department for Education (DfE), saying it did not trust the accuracy of its figures. Now the committee had decided to examine the financial affairs of the Durand academy in south-west London – a school that had been held up as a flagship for the academy programme by the former education secretary, Michael Gove, and whose head, Greg Martin, was knighted for services to education in 2013 – to see if they could shed any light on where the department might be going wrong.

“Let’s get this straight, Sir Greg,” said Hodge. “You transferred the school from the Durand Academy Trust to the Durand Educational Trust in order to avoid paying corporation tax.”

Martin nodded enthusiastically. “Why bother giving the money back to the government when I can distribute it myself?” was the gist of his reply. “Because that’s a decision for the government to make,” Hodge snapped back. Martin was outraged. All he had ever done was for the benefit of the children and it was thanks to him that the academy was planning set up a state boarding school near Midhurst in Sussex.

Hodge then wanted to ascertain the exact legal status of the school’s finances. “Can you help with that, Sir Peter?” she asked Peter Lauener, chief executive of the Education Funding Agency, before correcting herself. “I’m sorry, you’re not Sir Peter yet.” Nor likely to be any time soon on this performance, as it turned out that though he did believethe £5m in question still belonged to the DfE he couldn’t really be certain about it. “It’s very difficult,” he sobbed abjectly.

The committee moved on to London Horizons, a company that had bought some of the school’s assets and turned them into a private gym.

“We still allow the schoolchildren to use the pool,” Martin added generously. He had also, out of the goodness of his heart, saved London Horizons the sweat of running the gym; his own private company, GMG, had been doing it for them. “The company donated £630,000 back to the school last year,” Martin said. It also donated more than £165,000 to Martin’s back pocket – on top of the £230,000 he earns for running the school. The five staff members at the gym earned £95,000 between them. There’s a lot to be said for the minimum wage.

Things became even more testy when Hodge moved on to another of Martin’s activities: a dating agency in which he had a financial interest that was run from the school. “There’s a Twitter account in the name of Saffron that features semi-nude women and all sorts of black underwear,” she said. “Do you think that’s appropriate?” Martin thought it was none of her business what he did in any break from sweating the school assets and it was just a coincidence that the agency had the same address as the school.

“What this country really needs is more headteachers like me,” Martin snapped. The DfE appears to agree. Hodge didn’t. “This isn’t about standards at your school,” she smiled sweetly. “Though I do notice Ofsted has downgraded your school from outstanding to good.”