In an unprecedented move, the college’s chair of governors, Sue Georgeous, was made interim chief executive.

As the turmoil at the college escalated this week, UCU issued a demand for the college to open its books because of the discovery of “bumper pay rises” for senior managers and the payment of hundreds of thousands of pounds to a body co-founded by Ms Cavalli.

In May the college announced a budget shortfall of £3 million and Ms Cavalli said job losses were “inevitable”.

It later emerged up to 99 jobs were at risk.

The UCU said that a Freedom of Information (FOI) request had revealed that Ms Cavalli’s salary had rocketed from £170,000 a year in 2011-12 to between £220,000 and £230,000 in 2013-14, an increase of more than £50,000 (a rise of up to 35 per cent in two years).

By contrast the staff at the college had seen their real-terms pay fall by 16 per cent in the past five years. This year they were offered another below inflation pay rise of one per cent.

And one unnamed senior manager, according to the UCU statement, enjoyed a bonus of £15,000.

But perhaps the most intriguing revelation, following the FOI request, is that Warwickshire College has given more than £500,000 to what UCU calls “the controversial Gazelle group of colleges”, of which Ms Cavalli was a co-founder in January 2012.

The UCU statement said Warwickshire College paid £35,000 a year to be a member of the Gazelle group of colleges.

“According to reports, the college has spent more than £200,000 on purchasing shares in Gazelle Transform Ltd and a further £324,000 for services in connection with developing a ‘new education concept’ with Gazelle Global Ltd,” the UCU statement added.

On its own website, the Gazelle Colleges Group says it was formed in January 2012 “to transform further education for a changing world of work”.

Its website statement adds: “It is developing innovative new learning models and new partnerships with business to deliver an improved outcome for students, their communities and the economy.”

UCU regional official Anne O’Sullivan said: “Almost 100 members of staff at the college might lose their jobs, pay has been driven down in recent years and yet we are starting to uncover details of massive pay rises for a principal now on leave and for other senior managers.

“The college needs to open its books up and ex-plain why such large sums were given to the Gazelle Group of Colleges and what new education concepts are and why they cost £324,000.

“We also need to know what has been spent on overseas travel and expenses, why senior managers got such big pay rises and who is getting a bonus on top of their salary and why.

“The time has come for proper scrutiny of colleges’ spending. We would urge the Public Accounts Committee to properly investigate how taxpayers’ money is being spent by our colleges.”

Last week Ms O’Sullivan had a meeting with the interim chief executive and her deputy, who told her that the college would be maintaining its links with Gazelle.

In a statement to the Herald Fintan Donohue, Gazelle’s chief executive, said the £3.5 million given to Gazelle represented the total investment in the enterprise over the past three years.

Gazelle was now made up of 23 colleges, whose total budget over the three-year period was approximately £1.6 billion.

He added: “The 23 members of the Gazelle Colleges Group all invest £30,000 per annum, which represents a relatively small proportion of their annual budgets for business engagement, staff development and student experience into the work of Gazelle.

By sharing resources they benefit from economies of scale and better value for students.”

Meanwhile the board of governors of Warwickshire College said it was unable to comment further on the principal’s temporary leave of absence.