The long-vacant 25-metre tall buildings are being gutted and razed as developer Amalgamated Property Group clears the site for future development.

The Graham Potts-led company has previously signaled its intention to transform the block with a mix of apartments and commercial space, although it has yet to unveil those plans or lodge a development application.

It has not returned calls from The Canberra Times.

Built to house the old Bureau of Mineral Resources, the predecessor to Geoscience Australia, the block has sat vacant since its last government tenants vacated in 1997.

The asbestos-contaminated building has since become a target for vandals, creating a eyesore for the thousands of motorists who pass through the Parkes Way/Anzac Parade intersection every day.

In 2014, The Canberra Times reported that in the previous five years, the government had spent $1.6 million maintaining the buildings.

The federal government revealed in 2016 plans to sell Anzac Park East and Anzac Park West, as part of a wider sell-off of ageing government buildings in the parliamentary triangle.

The news angered heritage advocates, who feared the view from Parliament House to the Australian War Memorial would be ruined unless Anzac Parade's so-called "portal buildings" were redeveloped simultaneously, and in symmetry.

That is unlikely to happen after different developers bought the two sites.

While Amalgamated Property Group must develop its block within the next four years, Anzac Park West - which was purchased by EG Funds Management Pty Ltd for $51- could remain standing long beyond that because of a long-term lease with Department of Defence.