Irrigators have been accused of stealing billions of litres of water from the Murray River system, while government authorities do nothing.

A Four Corners report this week exposed what one farmer called “the biggest water grab in Australia's history”.

“What we're seeing quite clearly is that environmental water bought by taxpayers is going through pumps into storages to grow cotton,” another interviewee stated.

The report reveals that some irrigators are thwarting the Murray Darling Basin Plan by illegally taking huge amounts of water for their own use.

Most of the theft is allegedly happening along the Barwon River, and further allegations suggest certain NSW government bureaucrats have turned a blind eye to the practice.

“There is no question in my mind that the majority of Australians supported the expenditure of a huge amount of money - $13 billion - to fix the river. If a number of irrigators have got a huge windfall out of this, I think everybody will be disgusted,” cattle farmer and former NSW Farmers Association President Mal Peters told the ABC.

A number of significant figures have spoken out since the story landed.

“We're outraged, we suspected it, but every time we raised it every politician would push back on us,” said Broken Hill Mayor Darriea Turley.

Australian Conservation Foundation Campaigns Director Dr Paul Sinclair said: “Communities across Australia and in the Murray-Darling Basin deserve to know why it appears laws to stop the theft of water flows haven't been enforced by the NSW Government. These are serious allegations of extraordinary abuse of the Murray Darling Plan. There must be an ICAC investigation”.

Australian Floodplain Association president Terry Korn said: “The Four Corners show has highlighted the inability of the current NSW Government to develop, implement and monitor effective water management policies. As a result we see the health of the Darling River and its tributaries decline and the non-irrigation communities it supports suffer death by a thousand cuts”.

“There needs to be an independent judicial review,” said South Australian Water Minister Ian Hunter.

“This strikes at the very heart of the public service in New South Wales, if the allegations are correct. If you don't have confidence in the amount of water that's being taken out... then you can't actually have any compliance under the plan whatsoever,” he said.

NSW Water Minister Niall Blair has ordered an independent inquiry into the State Government's handling of the issue.

Additionally, NSW’s most senior water bureaucrat has referred himself to the state's anti-corruption watchdog, after it was revealed that he offered to share confidential government information with irrigation lobbyists.

It has also been revealed that Deputy Prime Minister Barnaby Joyce nominated an irrigation lobbyist to the board of the Murray-Darling Basin Authority (MDBA), and that a community officer for the MDBA works for Clyde Cotton, a major irrigator at the heart of the story.