The NSW environmental watchdog has asked the Independent Commission Against Corruption to examine allegations it had botched investigations of illegal waste activities in the state.

The referral on Wednesday to ICAC came just a day after the Environment Protection Authority defended its performance against claims of corrupt activities raised in ABC's Four Corners program on Monday.

Tensions between the government and the waste industry were strained further on Wednesday, with the EPA cancelling a long-standing meeting with representatives just before it was due to begin. The agency blamed members' involvement in the ABC program, one executive said.

Barry Buffier, chair and chief executive of the EPA, said the anti-corruption agency should examine the claims of illegal dumping and his authority's handling of the matters.