Work being done at the Saddle Hill quarry was authorised under an agreement between the quarry and the Dunedin City Council, Cr Colin Weatherall said.
Cr Weatherall said diggers had been working on the upper levels of the quarry, but that was "no surprise".
Quarrying on Saddle Hill has been a controversial issue for years, because of its effect on the shape of the hill.
After concerns from neighbours work was to expand, the council in April asked the Environment Court to clarify the legality of the quarry, owned by Saddle Views Estates.
The council reached an agreement recently with the owner, company director Calvin Fisher, and the quarry operator, over what quarrying could take place while the future of the facility was being negotiated.
The operators were allowed to clear the upper slopes of loose material to ensure the safety of workers, but the skyline outer rim would be retained while discussion was under way.
The clearing of that material was the work being done, Cr Weatherall said.
