Found during excavation, work was immediately stopped near the shaft, which is at south-eastern end of the construction site, near Nolan Street.

Experts from Heritage Victoria and Regional Development Victoria were called in on Friday morning to examine the site, and assessed it appropriate to fill for safety.

Investigations have begun, and depending on what they reveal, the timing of the car park’s opening may be affected.

READ MORE: Historic mineshaft opens in Ballarat

No other shafts have been found on the site so far.

 An RDV spokeswoman said the contractor, Pellicano, is working with the state government to get the car park open as soon as possible.

“(The government and Pellicano) will follow the advice of mine shaft experts and Heritage Victoria to ensure this unexpected discovery is dealt with safely and appropriately,” she said.

Infrastructure and environment director Terry Demeo said the council will assist contractors and agencies at the station precinct.

“However, in respect to physical works the site is under the contractor's control completely and it is state government-controlled land, hence council will not be involved in physical works,” he said.

READ MORE: Wallaby safely rescued from mineshaft in Invermay north of Ballarat

Mineshafts on road reserves and public land are capped by the council, and it facilitates the capping of mineshafts that open on public land.

Mr Demeo said it was a regular occurence.

“Historically, the shafts were capped with timber but many of these caps are getting towards the end of their life,” he said.

“Council deals with one to two instances per year on average, which sees these shafts capped with steel/concrete now as a ​standardised practice.”

Warrens of historic mines still exist below Ballarat, while working mines are much deeper – there is one near the station, according to GeoVic maps.

A map from Visualising Ballarat, a joint council and Federation University project, showing known mineshafts in Ballarat Central.

Many are still unregistered and unmapped, though mapping projects, including a joint project from Federation University and the City of Ballarat, are helping to find them through newspaper and company records.

The Nolan Street site is near the mine that produced the 69kg Welcome Nugget in 1858, which is the second-largest gold nugget found in the world.

The multi-level car park is almost finished, and was expected to be opened to commuters in January before other works begin.

The Courier incorrectly reported a public information session would be held on Friday December 7. This was not correct and no meetings will be held at The Provincial Hotel on Lydiard Street.

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