Ex-Greens MP Jeremy Buckingham has discovered the magnitude of the Murray-Darling toxic algal bloom crisis first-hand, wretching on camera after being overcome by the almighty stench.

The now-independent New South Wales MP met with Menindee farmers Dick Arnold and Rob McBride, following their social media plea that has been viewed millions of times.

Handling a decomposing Murray cod, Buckingham slammed the Nationals over its handling of the river system.

Tweet from @greensjeremy

“It’s a national disgrace, this once magnificent Murray cod is dead, and it absolutely stinks,” he starts out, evidently affected by the aroma emanating from his surrounds.

“The fish kill in the Darling River that we have witnessed, that Dick and Rob have put on social media and is going viral is an absolute catastrophe.

“This magnificent animal must be generations old and now is dead and rotting here and it absolutely stinks.”

Up to a million local fish have perished in the smothering conditions caused by the blue-green algae event.

Appearing visibly nauseous, the stench and appearance of the surrounds was overwhelming, halting Buckingham’s diatribe before he proceeded to retch off-camera.

The MP eventually returned to the bank, asking those around him about the state of the cloudy water below, before diving into the river that houses scores of rotted fish.

“It was one of the most disgusting experiences of my life. I felt so sick that I panicked and jumped in the river to escape it – as bad as it is!” Buckingham said in a tweet accompanying the video.

Fish crisis a ‘man-made disaster’

The video follows calls from the New South Wales government for an investigation into the mass fish deaths, which local residents in far western NSW are labelling a “man-made disaster”.

NSW Primary Industries Minister Niall Blair says he has requested an urgent report from the Department of Primary Industries and Water NSW.

The minister says he has been criticised by locals claiming a lack of water supply is due to amounts diverted to irrigators, but insists none are in place because of the prolonged drought.

Rob McBride, a grazier on the Lower Darling who featured in the initial viral video, insists the deaths are the result of a “man-made engineered disaster.”

“It has everything to do with the total mismanagement and corruption of the water system,” Mr McBride told AAP.

The NSW opposition has demanded an inquiry into the state’s water management system, declaring one with “royal commission-like powers” will be established if they win government in March.

“The scale of this disaster is extraordinary and unprecedented,” opposition leader Luke Foley said in a statement.

Premier Gladys Berejiklian assured angry residents in the region the government was working to find “solutions”.

-with AAP