West Australian police are investigating Clive Palmer following allegations he fraudulently used $12 million from a Chinese company to fund his political campaign.

The Palmer United Party leader is being sued by Chinese-government owned Citic Pacific, who claim Mr Palmer used funds intended for the running of a WA port to promote his political party during the 2013 federal election.

• Clive Palmer extends olive branch to Jacqui Lambie
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Citic Pacific representatives have reportedly handed evidence to West Australian police amid an ongoing civil case due to begin in Brisbane’s Supreme Court on Wednesday.

WA Deputy Police Commissioner Stephen Brown said police were looking into materials received from the Citic Group.

“I can confirm that we have received materials on behalf of the Citic Group and we’ve commenced to assess those materials to determine whether there’s been any criminal activity, as part of our normal fraud investigation and assessment process, and that’s the only comment I will make on that matter,” he said.

Mr Palmer has vehemently denied the allegations, saying the claims brought against him are “untrue”.

He told Fairfax radio that all money paid to his companies was for services they did.

“It was all declared on the public record and what they did with the money,” he said.

The mining magnate stormed out on an interview on ABC’s 7.30 last week when probed about the case, alleging Citic Pacific owed him hundreds of millions of dollars in iron ore royalties.