Thousands of workers have been given the all-clear to re-enter the Benjamin Offices in Belconnen after they were evacuated by firefighter crews investigating a smell of smoke around 1pm on Tuesday.
Approximately 5000 workers were forced out of the offices on Chan Street for more than an hour, but no active fire was found.
ACT Fire and Rescue crews were on the scene, using thermal imaging equipment to try and identify the source of the smoke from the plant room.
Early indications suggested the air conditioning unit was causing the smell of smoke, but it was later found the smell came from the elevator motor room.
The air conditioning unit did however disperse the smell through the area.
The Hazardous Materials Unit assisted as the ACT Fire and Rescue ventilated the building and monitored the atmosphere before staff returned.