TORONTO -- Ontario's auditor general opened the education ministry's books to examine $3.8 million in payments to unions, but was "surprised" to find an additional $80 million in funding, about a quarter of that with "no strings attached."

Bonnie Lysyk had been asked to investigate money the government paid unions representing teachers and education workers over the past three rounds of negotiations, which were longer than normal due to a new bargaining system.

Lysyk said in a report released Wednesday that those payments were unusual, but within the government's authority. The concerns raised about the payments, revealed in media reports, were "understandable," Lysyk wrote.

"These arrangements initially lacked accountability and the controls usually associated with government funding," she wrote. Only after the auditor's office was asked to investigate did the government ask the unions for expense reports, she said.

The auditor's office was unable to find evidence of any other government in Canada paying for bargaining costs of education-sector unions.

Going back to 2000, Lysyk said her office was "surprised to learn that the government had given teachers' unions other sums totalling more than $80 million." An additional $6.8 million was given to school boards to provide to the French teachers' union for professional development, Lysyk found.

Of the $80.5 million, Lysyk said $22 million was provided with "no strings attached" and the remainder was largely earmarked for teachers' professional development. The rest of the money went to benefits, research and initiatives such as school safety and eliminating discrimination.

"The ministry has little information as to what these funds were actually used for," she wrote. "One might reasonably ask why such funds were not provided to various school boards throughout the province for their own locally determined professional development needs."

Though three other provinces gave teachers' unions money for professional development in the last five years, Lysyk found, none paid more than $2 million in total.

Education Minister Liz Sandals defended funding professional development and said the payments were not taken out of classroom spending. The bulk of professional development is done through school boards, but the unions have well-established professional development departments and provide valuable training, she said.

The $22 million in unconditional grants was given out in 2006, under accounting rules at the time that are no longer the practice today, she said.

"I agree that the 2006 accountability wasn't great," Sandals said.

The Ontario Secondary School Teachers' Federation said it has received just over $6 million since 2006 for professional development. During that period the union has delivered more than 1,000 workshops, six provincial conferences and dozens of regional symposia, the union said.

"The most recent funding we have received, for example, supports the teaching and learning of mathematics in schools across the province," said president Paul Elliott.

The Elementary Teachers' Federation of Ontario said its professional development materials are "renowned, and known and used internationally."

Other findings by the auditor include:

-- When submitting bargaining expenses for last year, the unions were allowed to set their own rates for travel, meals and hospitality. The union daily meal rate was $80, compared to the $40 rate used by the public service.

-- In 2012 bargaining, the larger unions' expense statements "far exceeded" the maximum amounts. So the ministry increased the maximum amount.

-- Though the ministry has publicly said the education contracts were net zero, meaning any cost increases were offset by savings elsewhere, it told the auditor the estimated financial impact over the term of the agreements could range from $40 million in savings to $66 million in extra costs.

Sandals said in a $23-billion education budget, that would still be "very close" to net zero.