Finder.com.au allows users to compare services in several industries, such as energy and gas, telecommunications and financial services.

Between February and May this year, Finder's website stated that its health insurance comparison service allowed customers to "compare roughly 65,000 policies".

However, the ACCC said the number of policies actually compared was "substantially less than this".

"In our view, this was misleading and likely to divert consumers away from other online comparison services," ACCC deputy chairwoman Delia Rickard said.

"Consumers increasingly rely on comparator platforms to inform their choice of insurance provider, particularly when faced with a large range of policy options.

"Operators of comparator websites must ensure that the claim they make about market and product coverage are accurate so that consumers can make fully informed decisions."

The claim was published during what is known as the industry's annual "switch period", when Australian health funds typically announce their annual premium "rate rises".

Customers often look to change insurance policies and providers at this time, in many cases using online health insurance comparators, such as Finder, for guidance.

Finder has since paid penalties totalling $10,800 to the watchdog for allegedly breaching consumer law and removed the claim from its website.

But Fred Schebesta, co-founder and director of Finder, said that the company had no intention of misleading customers.

"The original figure took into account policy variations including state and structure of offers, with each variation generating a different price," Mr Schebesta told Fairfax Media.

"While there was no intent to mislead our customers, we regret any confusion or inconvenience."

Mr Schebesta nonetheless claims the website continues to "compare more health funds and policies than any other competitor and remains committed to helping millions of Australians make better informed decisions".