Hotel comparison website Trivago is being sued for making misleading claims.

The Australian Competition and Consumer Commission (ACCC) has taken action on allegations that Trivago has deceived consumers by claiming to be an “impartial and objective” aggregator.

The ACCC will argue that Trivago's search results prioritise advertisers who pay more.

“When you look at a lot of Trivago's television advertising ... and I've seen a lot of it, it's often suggesting; ‘Get on Trivago and find the best price’,” ACCC chairman Rod Sims told the ABC.

Trivago and similar comparison sites “give the impression they're there to help consumers when in fact they're there to help suppliers who pay them the most money”.

Mr Sims said the ACCC has been looking into the issues after hotel operators realised “they were cheaper [but] weren't getting prioritised”.

“We're alleging Trivago's website is deliberately designed to mislead consumers.

“We looked at Trivago algorithm and formed the view that it was misleading in terms of the way it presented options to consumers,” he said.

The regulator is also investigating other comparison websites similar to Trivago.