UPDATE: THE smoke was caused by an appliance fault, according to ACT Fire & Rescue in a 4.15pm update (Tuesday, March 12).
Firefighters conducted atmospheric monitoring and air ventilation operations to ensure the area is safe and have handed the property back to the building manager.
The southbound lane at 161 London Circuit, City has been reopened and firefighters have since departed.
ONE southbound lane on London Circuit has been closed after smoke was reported in an office building located on 161 London Circuit.
The area has been evacuated and crews are investigating the source of the smoke.
ACT Fire and Rescue is urging the community to avoid the area where possible.
ACT Ambulance Service paramedics and ACT Police are also on scene.