AUGUSTA — The ethics commission voted today to further investigate the campaign finance activities of the Lewiston casino, ruling that there was sufficient evidence to show that a violation may have occurred.

Dennis Bailey of CasinosNO! filed a complaint with the commission asking it to look into whether two political action committees controlled by casino backers fully reported who contributed money to try to convince voters to support a November ballot question. Voters rejected the casino by a wide margin.

Peter Robinson of Green Jobs for Maine told the commission today that the reports are accurate and that he’s frustrated that Bailey is insinuating otherwise. Nearly all of the money to fund the campaign came from GT Source, a Georgia company that makes gaming equipment, he said.

“I’m taking exception to this implication that we got caught and now we’re changing our story,” Robinson told the commission.

The commission voted to ask staff to continue an investigation because GT Source has refused to answer questions about its contributions and there is little information about who is behind Dome Messaging, a group hired to do polling and media buys for the campaign.

Commission Chairman Walter McKee said the investigation may not find any violations, but that they would “be remiss if we don’t follow up on it.”