The Maine ethics commission will decide Wednesday whether to probe the campaign finance reports of the political action committees behind a failed proposal to allow a casino in downtown Lewiston.

A complaint lodged with the ethics commission last month by anti-casino group CasinosNo! questioned the source of $412,000 in contributions to two PACs, People of Lewiston Auburn Committee and Green Jobs for ME, which supported the statewide casino initiative that voters resoundingly rejected in November.

The ethics commission staff has started to look into the complaint and is recommending that the commissioners authorize the investigation to continue.

A key document in the preliminary investigation was an agreement signed by the manager and members of Great Falls Recreation & Development LLC, the Lewiston company that had an option to buy Bates Mill No. 5 from the city to develop the casino.

Under the agreement, a corporation called M Five Inc. would have acquired that option from Great Falls — a deal that would have required approval from the Lewiston City Council.

No one from M Five had signed the proposed agreement, which was provided to the ethics commission by CasinosNo! spokesman Dennis Bailey, who wouldn’t say how he got the document.

In a Dec. 22 letter to the commission, Bailey noted that one of the officers of M Five is Dwayne Graham. Graham is also the chief executive officer of GT Source, a Georgia slot machine company that made about $412,000 in contributions to the political action committees, which was the vast majority of the campaign’s funding.

“Our question is, what was the true source of the funds for the PAC? Was it GT Source or M5? Was GT Source merely the conduit of funds from M5 and if so, is that a violation of campaign finance laws?” Bailey wrote in his letter.

Bailey also questioned the existence of a Virginia company called Dome Messaging, which the PACs reported paying to create promotional material for the campaign.

On Dec. 28, the ethics commission staff wrote a letter to the PACs asking for a response to Bailey’s complaint and requesting documents, including copies of checks and receipts, to verify the reported payments from GT Source and to Dome Messaging.

Peter Robinson, who performed the financial reporting for both PACs, responded to the letter by asserting that the finance reports were accurate, though he said he would need more time to produce the documents to back them up.

Jonathan Wayne, executive director of the ethics commission, also wrote a letter to GT Source on Dec. 28, asking for documents to verify the company’s reported contributions to the PACs. Graham, the CEO, wrote in an email to Wayne that neither he nor the company “intend to respond to your request at this time.”

The ethics commissions staff is recommending that the commission continue to ask for documents verifying contributions from GT Source and other donors, as well as checks and invoices exchanged between the PACs and Dome Messaging.

The commission will consider that recommendation at a 9 a.m. meeting Wednesday at its office in Augusta.

Wayne said if finance reports are found not to be “substantially correct,” they can be considered late — a violation punishable by a fine of up to $10,000.

Bailey said Friday he doesn’t know what an investigation into the finance reports might find, but is pleased that the ethics commission staff is recommending to look into them.

“I was glad that they smelled something,” he said.

Stavros Mendros, the manager of Great Falls and the casino campaign, said Friday he expects the ethics commission to throw out the request and insisted that there’s nothing suspicious about the campaign’s finances.

“This is just Dennis Bailey using taxpayer money on a ridiculous witch hunt. … He plays mysterious music in the background and makes it seem like something’s going on,” Mendros said.

He said Bailey, who was fined by the ethics commission last year for his involvement with a website attacking gubernatorial candidate Eliot Cutler, should understand reporting requirements “better than anyone” and should know that the PACs followed them.

Mendros accused Bailey of pushing the issue for his own financial gain.

“It’s just Dennis Bailey trying to get his name in the paper so he can get more clients,” he said.

Bailey said he would drop the issue gladly if he believed Mendros and others behind the proposal weren’t going to keep trying to bring a casino to the state; but Bailey said he believes “they’re going to be back,” and he wants their contributors confirmed before then.

“There should be full disclosure,” he said.

Mendros said there are efforts under way to put a proposal on the ballot in 2013 for a casino in Lewiston, where the majority of residents voted in favor of the last initiative.

“The citizens of Lewiston still want this,” he said.