According to reports a bomb threat was phoned into the headquarters just before 11am, leading to staff being evacuated from the building in Pyrmont, Sydney.
It comes on the day several news staff are expected to be told they are facing redundancy, as the network looks to cut costs after losing more than $12m last financial year.
Police are currently on the scene, but it is unclear when staff will be allowed to return to the building.
Ten was unavailable for comment at the time of publication.
Update: In the afternoon, staff were allowed back into the building.