Marked and unmarked police cars with at least six officers, some in bullet proof vests, were at the scene from 6.30am on Friday although there was no suggestion of any conflict.

Police said a community contact told them that a man had an unregistered firearm at the Theodore house.

They seized some weapons from the garage during the search.

ACT Policing Senior Constable Darren Fitzroy said the the man also owned registered firearms.

He also said the man was compliant and assisted police in their search.

No charges have been laid at this stage, but Senior Constable Fitzroy said it was likely charges would be laid in relation to possession of the prohibited firearms.

Superintendent Justine Gough confirmed the firearm seized was unregistered.

"While many firearm owners are responsible about the storage and licensing of all their weapons, this incident stands as a reminder to those owners to review their records and ensure they comply with licensing regulations," Superintendent Gough said.