The Victorian government is pursuing criminal charges against the former owner of the Ballarat gold mine for unpaid rehabilitation bonds, in the latest regulatory probe into a mine that this week suffered a partial collapse that killed an underground worker.

Unions renewed their long-standing concerns about safety standards at the Ballarat mine on Thursday after a 37-year-old miner, identified in media reports as Kurt Hourigan, was killed when he and another worker were pinned underneath fallen rocks 500 metres underground.