Water safety specialists are warning that some wellness centres could be making Australians sick, with contaminated spa pools straddling a fine line between relaxation and contamination.

As wellness centres explode in popularity across the country, experts say not every operator is maintaining proper hygiene standards, potentially exposing customers to dangerous bacteria.

WATCH THE VIDEO ABOVE: Spa health warning over contamination risks

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“Some centres we’ve been to, you probably wouldn’t let your worst enemy into the water,” Brauer Industries’ Luther McLachlan said.

“They’re taking shortcuts, they’re putting in a pool, they’re putting in a backyard system, and it just can’t keep up and it’s making people sick.”

The concerns centre around dangerous pathogens like cryptosporidium and legionella that come off people’s bodies, as well as faecal contamination in the systems.

“A faecal smear between your cheeks is enough to have an effective dose,” Griffith University microbiologist Associate Professor Helen Stratton said.

Wellness centres could be making Australians sick, water safety experts warn Credit: 7NEWS

Water safety experts testing spa water. Credit: 7NEWS

Spas are riskier than public pools because of their small size and high body count, meaning visitors could potentially be bathing in a toxic soup.

A sample taken from one unnamed centre showed contamination levels four times above expected levels. However, when treated properly, the same water can be clean enough to drink.

Experts say there are warning signs to look out for before stepping into a spa. The water should look clear and not smell of chlorine.

“That’s when chlorine’s attached itself to urine. There’s no smell. I can put my head underwater and my eyes don’t hurt,” McLachlan explained.

While local councils are responsible for making sure operators do the right thing, when laws are also murky, wellness centre visitors enter at their own risk.