Doubts have emerged this week over the Government's ability to remove academy sponsors who break the law.
Questions were raised as David Ross, the multi-millionaire co-founder of Carphone Warehouse and sponsor of Havelock Academy in Grimsby, became embroiled in a scandal over his financial dealings.
Mr Ross quit the board of Carphone Warehouse after it emerged he had broken City rules by failing to disclose that he was using his shares as collateral on loans.
It is understood that the Financial Services Authority, the City watchdog, has launched an investigation into his actions. Depending on the outcome, Mr Ross, a Tory party donor, could face criminal charges.
A spokeswoman for the Department for Children, Schools and Families said someone with an existing criminal conviction would not be able to become a sponsor.
But the DCSF was unable to say whether it would be able to remove a sponsor who subsequently broke the law.
The fallout from Mr Ross's situation has seen the tycoon, who was last year estimated to be worth Pounds 900 million, resign from his position as London Mayor Boris Johnson's senior Olympics adviser, and as chairman of the transport group National Express.
It has reignited concerns about ceding controls over state schools to private individuals and companies and comes just two months after The TES revealed that Amey, the sponsor of Unity City Academy in Middlesbrough, has become the first backer to say it wants to sever ties with its school.
Mary Bousted, general secretary of the Association of Teachers and Lecturers, said: "There are increasing problems with academy sponsorship. One has walked away, and now we have another accused of financial irregularities.
"This adds to the concern about who should own, run and govern our schools. Academy sponsorship is starting to unravel."
John Bangs, head of education at the National Union of Teachers, predicted that problems with academy sponsors would intensify as the economy deteriorates.
"The issues with David Ross and recently at Unity City Academy are straws in the wind of what will happen when the recession deepens," he said. "You cannot rely on the vagaries of the financial markets to keep the public sector education system going."