A top NSW bureaucrat was on Tuesday refusing calls to stand down despite allegedly offering privileged access to government documents to irrigation lobbyists.

But it was NSW itself facing unknown repercussions as other states agitated for action on the apparent theft of water in apparent breach of an agreement, following complaints from politicians in South Australia and Victoria.

Both Gavin Hanlon and former Water Minister, Kevin Humphries, were referred to the anti-corruption watchdog following an expose by the Four Corners program alleging NSW irrigators diverted billions of litres of water intended for environmental use.

Late on Tuesday, ​Simon Smith, secretary of the DPI, issued an email to staff saying that minister Niall Blair had asked him to "commission an arms length, independent review into the matters raised".