Minister for the Hunter Jodi McKay said the Land and Property Management Authority staff inspected the site yesterday.

"They are working with EnergyAustralia to get the supply of electricity disconnected to ensure the interior of the building is safe," she said.

"They are also implementing additional security measures and I urge people to remain outside the security fencing and not attempt to enter the building for their own safety. "

Ms McKay said the inspections revealed a number of problems with the building's condition, many of which were common to heritage buildings.

" . . . . the roof appears to be leaking and the basement area is flooded with contaminated water," she said.

A team of engineers, planners, heritage and environmental consultants and tradesmen have been assigned to work together to solve problems as they were uncovered.

An expression of interest process is due to begin in August providing the private sector with an opportunity to be involved in redeveloping the building.