Australia's father-and-son fugitives have gone to ground again.

Police thought they had a strong lead when Gino and Mark Stocco stole fuel from a gas station in southern New South Wales.

That was on Saturday night...but since then the trail has gone cold.

Police spokesman Bob Noble says when the pair are eventually caught, they'll face attempted murder charges.

"Obviously we've got an area here where there's been a number of sightings in recent days but clearly they've shown a propensity to cross borders and the situation is very fluid."

The men have been on the run since shooting at police 10 days ago.