Police and firefighters were called to the Indonesian embassy on Monday morning after a suspicious white powder was found in the mail room.
Police said it was too early to tell whether the suspicious substance was linked to the executions of Andrew Chan and Myuran Sukumaran.
The white powder was deemed safe Tuesday morning after being analysed at ACT Pathology but police have not revealed what the substance was and their investigation into the incident are continuing.
ACT Policing co-ordinated a response from ACT Fire and Rescue, police and AFP protection teams after embassy staff reported the package at the building on Darwin Avenue, Yarralumla, about 10.45am.
Detective Sergeant Dave Turner said no one was evacuated from the embassy or treated for exposure to the substance.
He confirmed the powder was found in the mail room but could not say how it had arrived.
"The embassy contacted us after identifying what they thought was a suspicious package," he said.
"Our current information is no one came in contact with the substance. The appearance of the package itself alerted them.
"We don't know what was in the package. We have little information. Safety is the first consideration in these matters. We've just contained the package."
The package was transported in a sealed container to ACT Pathology at the Canberra Hospital for analysis.
The package was discovered less than a week after Canberrans held a vigil outside the embassy to protest the execution of the two convicted drug smugglers in Indonesia.
Sergeant Turner would not be drawn on the timing of the incident.
"The motive for the package will form part of the investigation," he said.
"We don't have information on that at the moment.
"There's no other cause for concern or suspicion at this stage."
An emergency services agency spokesman declined to give any details and said it was a police matter.
Police cordoned the area around the embassy as a safety precaution, and closed Darwin Avenue to traffic while the investigation was in place.
A hazardous materials van, two fire trucks and a breathing apparatus van were also at the scene.
The last firefighters left by 12.15pm.
The roads were reopened and embassy staff had returned to work about 15 minutes later.
Sergeant Turner said the AFP protection team would liaise with embassy staff about safety procedures.
"I think the matter was handled well," he said of the response.