The Ontario Power Authority has found another 20,000 documents related to cancelled power stations in Oakville and Mississauga, weeks after Energy Minister Chris Bentley told the legislature all documents had been made public.

All legislative business ground to a halt for a week while members debated a contempt motion against Bentley, which was triggered by the government's reluctance to release the gas plant documents to a committee.

Bentley did release 36,000 pages of emails and correspondence which the government said showed the cost of cancelling the two energy projects was $230 million, while the opposition parties said it was closer to $650 million.

The Conservatives and New Democrats are ready to pounce after the OPA announced it had turned over 20,000 more documents to the clerk of the legislature and apologized for not releasing them with the original batch.

Bentley issued a statement saying he had been advised by the OPA and by ministry officials "that all responsive records" were submitted in the original 36,000 pages released on Sept. 24, 2012.

Bentley says he's confident that both the OPA and the ministry acted in good faith and that no documents were intentionally withheld.