The New South Wales Resources Regulator had previously issued a prohibition notice to the operation west of Cessnock one day after a coal burst on May 17 that Yancoal classified as significant.

The notice was officially lifted on July 30 following the placement of additional controls. The changes included staff training in pressure bump identification and coal burst trigger action response plans in addition to de-stress drilling work.

"A further prohibition notice remains in place, which prohibits longwall extraction from the 293m chainage," officials for Austar, which has a payroll of about 200, said in a confirmation statement.

The mine will also perform controlled cutting under strict conditions up to this point, so that it can test additional controls in order to mitigate the risk of a future coal burst. It will maintain an exclusion area for works of about 50m.

Yancoal, which owns 100% of the nearly century-old Austar complex, is an arm of China-based Yanzhou Coal Mining. The mine's saleable coal production last year was 1.8 million tonnes.