Among a long list of allegations is that workers are being instructed by supervisors to attend mines when they are meant to be self-isolating and staff are being told social distancing doesn't apply at mine sites because they are "essential" businesses.

The NSW Resources Regulator confirmed on Wednesday night it was also investigating claims that some workers, who returned from overseas or have been in contact with known COVID-19 cases, are still attending work.

Miners have reported being forced to travel in groups in vehicles with no chance of maintaining social distancing, being required to use breath-testing stations with no safety controls and lacking facilities to ensure good personal hygiene.

The damning allegations come as another 31 cases of coronavirus have been diagnosed in the Hunter New England region in the 24 hours since the local health authority's last update, taking the total to 103.

The latest results have prompted one of the region's senior public health doctors to warn the virus is scattered throughout the region.

Hunter New England Health on Wednesday released figures up to 8pm Tuesday, which showed the largest jump in the number of cases in the region for a 24-hour period since the pandemic took hold.

Allegations that mine workers are being put at risk, come just a day after the Newcastle Herald reported the NSW Minerals Council praising the industry for pulling out all stops to protect workers.

The NSW Resources Regulator said the "business as usual" approach would not be tolerated and all worker complaints were being investigated.

A safety alert was issued to all mines on Wednesday afternoon reminding operators and workers of their responsibilities during the pandemic.

This includes enforcing strict social distancing, self-isolating where required and stringent hygiene practises.

"Under NSW WHS legislation, employers must have measures in place to eliminate or manage the risks arising from COVID-19," the watchdog said.

"Workers also have obligations to protect themselves and others.

"If a worker believes they or their colleagues are at risk of being infected with the COVID-19 virus while at work, they should raise their concerns with their manager as soon as possible."

Any workers not satisfied with the response are urged to contact the Resources Regulator.

The NSW Minerals Council said earlier this week that Hunter mines were operating as normal despite the introduction of extra measures to protect workers' health.

The Minerals Council spokesman said the industry was working with state and federal governments, regulators and other industry associations to assess and minimise the impact of coronavirus on the mining sector.

"Our priority is to ensure the health and safety of our workforce and mining communities while maintaining the strong economic contribution that our state, our mining communities and our mining families rely upon," he said.

"Mining operations are implementing extensive workforce protection measures in accordance with public advice, including enhanced cleaning and sanitation, work from home policies, social distancing in crib rooms and enhanced screening measures for visitors."

Some mines are taking workers' temperatures at the start of each shift to monitor signs of fever while others are staggering meal breaks and cancelling group meetings to keep workers apart.

But a Hunter mine worker told the Newcastle Herald on Wednesday night that not enough was being done to ensure workers weren't being put at risk.

"I don't think there anywhere near enough people taking this seriously," he said.

"Nothing has changed and you have to wonder if it's going to take a heap of us to get sick before anything does.

"There are too many people that think the government restrictions don't apply to them or to mines, it's ridiculous."

The Resources Regulator said all mines must review SafeWork Australia guidelines on how to protect workers, including increased cleaning of common areas, including vehicles and plant cabins.

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