It is suspected a creeping cancer that has decimated some of Queensland's best grazing country has crossed the border into New South Wales.

Keypoints: Meat and Livestock Australia are investigating a mystery grass disease that is wiping out pastures in northern New South Wales

Meat and Livestock Australia are investigating a mystery grass disease that is wiping out pastures in northern New South Wales It is suspected to be a creeping cancer that has destroyed grazing land north of the border in Queensland

It is suspected to be a creeping cancer that has destroyed grazing land north of the border in Queensland The pasture dieback makes grass unpalatable to cattle and causes weeds to move in, causing erosion risks and potential pest outbreaks

Pasture dieback has wiped out a good deal of grass throughout Queensland and researchers are racing the clock as they try work out what is causing the mystery grass disease.

The condition has been identified in all tropical and subtropical sown grasses and some native grasses too.

Now, Meat and Livestock Australia (MLA)'s dieback project manager Sean Starling and his team are investigating a report of the dieback on a property 100 kilometres over the Queensland–NSW border.

If the suspected case is confirmed, it will be the first report of the disease crossing the border.

Mr Starling said producers should not be alarmed yet but they should watch this space as updates come to hand.

"The word of caution there is the symptoms look very, very similar, if not identical [to dieback] but they are on different pasture species," he said.

A research team will go back to the northern-NSW site to dig underground and continue investigations for another two weeks.

Research efforts continue

The Queensland Department of Agriculture and Fisheries has been investigating the mystery condition for more than two years now.

An aerial view of a paddock near Middlemount in Central Queensland highlights the large areas of dead pasture affected by unexplained dieback. ( Supplied: ABC News )

Along with reducing pasture growth, dieback makes grass unpalatable to cattle, and a range of weeds and unwanted plants often move in afterwards, causing erosion risks and the potential for pest outbreaks.

MLA has invested millions in investigative research works over the past 18 months to better understand the extent of pasture dieback and potential causes.

Mr Starling said one potential cause they were investigating was that of bugs.

"It appears every time we look at what a cause might be a specific mealybug always seems to be in the pathway," Mr Starling said.

"At the moment MLA will not say that is 100 per cent mealybugs … we are not drawing the 100 per cent conclusion they are the only cause."

However the suspected case in NSW could throw a potential spanner in the works.

Scientists are still on the hunt for answers to the mysterious grass disease. ( Supplied: MLA )

Researchers on the site were unable to find any mealybugs.

"They will be going back with suitable digging equipment to dig underground and see if we can find these mealybugs underground," Mr Starling said.

"If there are no mealybugs on that property and it is confirmed as dieback, I think that definitely once again throws into the argument of are there other things causing this problem."

Keep eyes open

Mr Starling advised NSW farmers to keep their eyes open for symptoms as they went about their daily business.

Green pastures will start to go yellow on the tips, followed by more advanced yellowing and eventually the grass turns black.

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It usually occurs after good rainfall, but Mr Starling said that was not always the case and it was important for producers to keep their eyes open for dieback symptoms.

"Keep your eyes open for grass turning in a direction you're not expecting it to very quickly, especially after some substantial rain," he said.

Producers affected by unexplained pasture dieback are encouraged to contact the MLA.