A congressional ethics panel found that Rep. Mike Honda may have improperly used his campaign staff for campaign activity.

A congressional ethics panel announced Thursday that Rep. Mike Honda (D-Calif.) may have improperly used tax-payer funded congressional staff and resources for campaign activity in 2012 and 2014.

A report from the Office of Congressional Ethics (OCE) found that there “there is substantial reason to believe” that staffers assigned to Honda’s House office were involved in work that benefited his campaign. The OCE is an independent body that investigates ethics allegations and refers issues to the House Ethics Committee for further review. The Ethics Committee plans to extend its probe into Honda’s behavior.

“Representative Honda and members of his congressional staff may have improperly tied official activities, including a roundtable event with a State Department official, to past or potential campaign or political support,” the report said. “If Representative Honda improperly linked official activities to campaign or political support, then he may have violated House rules and standards of conduct.”

Honda acknowledged in a statement Thursday that members of his staff volunteered on his past campaigns, but denied that their activity violated House rules. He said that since the inquiry was launched, his office has developed new rules that clarify the line between official work and campaigning.

“As a result of the OCE investigation, I have instituted one of the most aggressive policies in Congress on the use of staff,” Rep. Honda said. “Even though the House Rules permit congressional staff to volunteer on their member’s campaign, I’ve erected a firewall in my office prohibiting this activity.”

Investigators found that some staffers felt that there was an implied expectation that they participate in campaign activity and felt pressured to comply.

“When asked if there was an expectation that she would work on campaign matters, the Former Legislative Assistant told the OCE, ‘That is a fair characterization of how that atmosphere worked. . . . Yeah, there was an expectation that you would help out,’ the report said.

Top aides denied those expectations.

House rules do allow congressional staffers to also work on a member’s reelection campaign. But their time has to billed separately and only after a staffer completes their official duties. Official resources, like office equipment and supplies, cannot ever be used for campaign activities.

Attorneys for Honda also argued that the work done by official staffers was legal and within the bounds of congressional ethics rules and any missteps were unintended.

“No credible evidence exists that the current or former staff interviewed by the OCE knowingly violated standards of conduct governing their actions or engaged in any material breaches of the separation between official and campaign-related activities established by the Committee,” Honda attorney Andrew Herman of the firm Miller Chevalier wrote in a letter to the OCE.

If investigators determine that he did violate House rules or standards, the committee could choose to formally discipline Honda.

Common punishments range from a simple reprimand to an official censure or a monetary fine.