The extension comes on the back of a large public demand for testing - more than 3290 tests have been undertaken over the first five days of operation.

"This is good news for the residents of Cessnock LGA who previously had to travel outside the LGA to be tested," Member for Cessnock Clayton Barr said.

Mr Barr has campaigned for a testing facility to be part of either Cessnock or Kurri Kurri Hospitals to bring Cessnock LGA testing rates up to similar levels as other LGAs in the Hunter region.

"The most encouraging thing is that out of the 320 tests performed in the opening five days, there were no confirmed cases."

According to data provided by Hunter New England Health the testing facility has been at near to full capacity for three out of the five days of operation.

Open daily from 10am to 6pm, residents have to book for an appointment by calling 4991 0436.

Figures available from NSW Data show over the last week the percentage of residents in the Cessnock LGA tested had risen to 3.9 per cent from 2.8 per cent the previous week.

Mr Barr said "The best way to prevent the spread of COVID-19 in the community is to identify sources of the virus through testing."