Officers attended the bar on Alinga Street at 12.30am on Sunday following a report the venue had exceeded coronavirus restrictions limiting the number of patrons allowed inside.

At the time, there were 32 people inside the bar when the venue's maximum was 28.

During their search of the bar, officers found there was no security on site and emergency exits were locked, despite the bar being in a basement.

An ACT police spokesman said the liquor law breaches led to the bar being closed for 24 hours, which kicked in just after 1am on Sunday.

ACT police coronavirus taskforce inspector Rachel Hutka said investigations were ongoing as to whether the bar had breached further coronavirus public health directions.

"We have generally found businesses keen to cooperate with us if there are any concerns regarding compliance with health directions," Inspector Hutka said.

"Businesses want to keep their staff and customers safe and the best way to guarantee that is by working with authorities."

It comes after two Canberra restaurants were fined $5000 earlier this month for breaching coronavirus patron limits.

A police spokesman said officers had also carried out more than 770 quarantine checks in the ACT during the past week with more than 11,000 conducted since the beginning of the pandemic.