The federal government was finalising plans to sell a disused restaurant in the Canberra's parliamentary triangle before Indigenous land rights activists began a controversial occupation this week.
Acting National Capital Authority boss Andrew Smith told Ngunnawal elders and Aboriginal Tent Embassy campaigners the future of the Lobby Restaurant near Old Parliament House had not been settled on Wednesday.
But documents provided to The Canberra Times show authority staff were finalising a commercial marketing campaign late last month, ahead of a sale through crown lease.
It is understood the building was to be put on the market within days.
One person was charged after police removed a group of activists from the Lobby on Thursday morning, a day after negotiations with leaders of the group failed to secure any resolution.
The man was arrested after a stand-off lasting more than an hour, as police escorted about five other members of the group from the building.
He was later charged with failing to leave a Commonwealth premise when directed and was released on bail to face court in December.
Activists forced their way into the restaurant on Sunday in an attempt to reclaim what they described as Ngunnawal sovereign land.
They issued the authority with an eviction notice and demanded $7 million in back-paid rent, before requesting a week's grace period to remain inside.
"ACT Policing were advised that permission provided to the group on Sunday, November 5, 2017, to remain in the building has now been removed and have been asked to restore the building to an unoccupied state," a spokesman said said.
"ACT Policing supported liaison between the NCA and the group's representatives in an attempt to negotiate a peaceful resolution."
Ngunnawal representative Serena Williams said it was seriously concerning plans to sell the building had not been publicly disclosed, accusing the government of lying.
"We live in this so-called capital of Australia. The government has failed to see our sovereignty of Ngunnawal land, Canberra is based on Ngunnawal country," she said from Darwin.
"We were asserting our rights, because we wanted to educate people on our past, our history, our land.
"They've failed to give us anything in the whole of the ACT and there's been dishonesty all together.
"There's more to come here. This isn't the end," she said.
Another activist described the group's removal as feeling like "a burst of tears".
'We've been pushed out and all that but it's one in a long succession of agonised [incidents] right across the country and that's what really gets you in the belly," the woman said.
Mr Smith repeatedly asked the group to leave the building this week, describing their occupation as illegal and unauthorised.
He was escorted into the building as police worked to remove activists, while media and supporters watched on.
Last month, the authority's senior officer for diplomatic properties and leasing had been involved in preparation of real estate marketing materials for the building's sale.
An authority spokeswoman confirmed planning for a sale had been under way.
"The NCA is always monitoring and reviewing its assets that ensure the best opportunities for the enhancement of the National Estate are pursued," she said.
"Within this remit, the NCA has investigated options to market the Lobby under a crown lease."
The building has been left empty after previous commercial tenants left before their lease expired, with it's prolonged vacancy prompting renewed land rights tensions around in the embassy encampment.
The Tent Embassy has occupied space in front of Old Parliament House since four Indigenous land rights activists started a protest on the site on Australia Day 1972.