The NSW government has been accused of abandoning the state's scientific heartland and putting priceless artefacts at risk as the Australia Museum guts its staff in a round of voluntary and forced redundancies.

Australia's oldest natural history museum has wiped out one-third of the permanent full-time equivalent employees, including all in-house security guards and several highly skilled research staff, the Public Services Association said.

Tough time: Australian Museum chief executive Kim McKay with Malagan masks from Papua New Guinea. Credit:Wolter Peeters

Of the museum's roughly 150 full-time equivalent employees, 50 jobs have been axed, amounting to more than 1000 years of scientific and historic expertise at the museum, the union said.

Museum management have disputed these figures, saying the FTE workforce was 206, which amounts to a loss of almost one quarter of staff through redundancies.