A council spokesman said archaeologist Wendy Thorpe had found stonework near the Goulburn courthouse that was likely to have been the base for the floor of the former jail. 

Work has stopped immediately on sewer relocation work and the council has contacted the Office of Environment and Heritage. This was a requirement if bushranger Thomas Whitton’s grave, remains of the old jail or other significant archaeological material was discovered. 

Ms Thorpe will prepare a report for the Office of Environment and Heritage over the weekend.

General manager Warwick Bennett said the discovery was not unexpected.

“We will work through these issues closely with the Office of Environment and Heritage. Although this may cause minor delays to the development of the Performing Arts Centre we intend to push forward and early indications from our archaeologist are that nothing is insurmountable,” he said.

While he only expects minor delays, the Goulburn Post understands it is not clear how far the stone extends.

The old jail behind the McDermott Centre (the proposed performing arts centre) was built in 1841.

The council expects to provide further detail to the community early next week.