A legal advocacy group has called for the Office of Congressional Ethics to investigate Rep. Duncan Hunter’s embrace of the vaping industry.

The California Republican is the same congressman who famously puffed billows from his vaporizer during a committee hearing last February.

The American Democracy Legal Fund sent a letter to OCE asking it to review Hunter’s “endorsement of private vaping products in blatant disregard of the House Ethics Rules,” the San Diego Tribune reported.

The group has criticized Hunter’s active embrace of the vaping industry, to the point he allegedly passed out one company’s business cards in Congress.

Watch: Hunter — ‘This is Called a Vaporizer’

Hunter’s spokesman, Michael Harrison, told the Tribune the attack is baseless and that Hunter supports a host of products he thinks will benefit his constituents.

“Congressman Hunter appreciates and supports the fact that the vaping industry is focused on harm reduction, meaning that vaping is an important tool utilized by many people to help reduce the harmful habit of smoking,” Harrison said.

Hunter is facing a criminal probe by the Justice Department into whether he used campaign money for personal use, the House Ethics Committee said in March. The committee said it was deferring its own inquiry at the DOJ’s request.

The fifth-term congressman reimbursed his campaign more than $62,000 for personal expenses, or those that lacked proper documentation, such as his son’s video games, a resort stay and jewelry purchases.

Hunter has claimed that he himself kicked the habit of smoking by using a vape.

Members of Congress are not supposed to officially endorse certain products, but it is often tricky for OCE to determine what counts as an official endorsement and what does not.

“The rules are there to ensure that Members of Congress don’t use their positions of power to favor specific companies, brands or industries or to benefit themselves or their personal interests,” the group’s president, Brad Woodhouse, said in a statement to the Tribune. “Congressman Hunter has violated the letter and spirit of rules against such activity and the Office of Congressional Ethics must investigate his blatant flouting of these rules immediately.”

Hunter has received roughly $20,000 from lobbyists representing the vaping and tobacco industries.

He has firmly denied any ethical wrongdoing.