Ontario taxpayers aren't on the hook for Ornge's debts, even though the government is virtually the only source of revenue for the troubled air ambulance service, a senior bureaucrat said Wednesday.

Ornge is solely responsible for repaying the $275 million it borrowed in 2009 by selling bonds, said James Sinclair, director of legal services for the Ministry of Finance.

In his testimony before a legislative committee, he said the prospectus made it clear that the province wasn't guaranteeing the bonds and wasn't legally obligated to repay the debt.

Ornge Issuer Trust is solely responsible for the bonds, he said.

Ornge, which had set up a web of for-profit subsidiaries, was supposed to generate its own revenue. All the entities are being shut down.

But under questioning by opposition critics, Sinclair was at a loss to explain where the money would come from, other than the government.

"So you're suggesting that Ornge Issuer Trust is now solely responsible?" said Progressive Conservative Frank Klees. "They have no income. How are they going to pay it?"

"I don't know the answer to that question," Sinclair said. "I'm not familiar with the financial affairs of —"

"Sure you are," Klees interrupted. "You're probably more familiar than anyone with the financial affairs of this trust. You know full well that the only income stream is from the government of Ontario."

Ontario's auditor general has said that Ornge's debt is on the province's books and the government is currently servicing that debt.

Ornge, which is currently under a criminal investigation, receives about $150 million a year from the government.