The Transport Canberra and City Services Directorate "authorised" a developer's temporary traffic management plan that included building a driveway on a private block of land without consulting the affected landholders.
Geocon sought permission to close Cameron Avenue as part of ongoing works at its Republic development in Belconnen, limiting access to a neighbouring building.
The solution proposed in Geocon's traffic plan was to cut a driveway through a garden bed which divides two neighbouring blocks to allow rear access.
The Sunday Canberra Times understands the separate owners of both blocks were not fully consulted on the plan, which would have seen private infrastructure used while the public road system was shut.
A spokeswoman for the directorate said the plan had been "authorised" on April 28.
"The [temporary traffic management] plan was not revoked, however, the contractor was directed by Roads ACT to remove the road closure with the [plan] until the amended development application process ... has been finalised," the spokeswoman said.
In a letter to neighbouring business owners on May 15, Geocon said its road block would be removed pending the outcome of a development application amendment.
The developer also said further consultation would be provided.
Transport Canberra and City Services did not respond to written questions about the proposed driveway on private land.
The directorate did not clarify whether there was a difference between an authorised and approved plan. The plan provided by the directorate to the Sunday Canberra Times does not have an approval stamp.
Earlier this month, the Sunday Canberra Times reported the transport directorate had approved Geocon's plan to block Cameron Avenue for several months without direct consultation.
The road closure was publicly notified on the directorate's website.
A directorate spokeswoman said it was the responsibility of the proponent to ensure surrounding businesses and landholders had been adequately consulted.
"It is the responsibility of the person submitting the [temporary traffic management plan] to ensure all directly affected stakeholders have been consulted with regards to any road closures and associated impacts," she said.
The directorate also endorsed a development application amendment lodged by Geocon that sought to remove disability permit car parking with no evidence the medical practices or building owners served by the car parks were consulted.
Belconnen Community Council chair Glen Hyde said at the time the process had highlighted gaps in the planning system.
"This particular process has left everyone confounded and dumbfounded," Mr Hyde said.