AUGUSTA, Maine — Ethics commissioners trying to figure out the source of a $4.2 million campaign to build a southern Maine casino say the women behind the campaign can only withhold certain documents.

Lisa Scott’s lawyer, Bruce Merrill, asked Thursday to withhold any financial documents that she thought was confidential or unrelated to the casino.

But the Maine ethics commission declined her request. Commissioners instead said Thursday she could withhold or retract certain documents, like communications with her attorney, and provide a log of such documents.

Scott has until Sept. 1 to respond to the commission’s June subpoena.

Maine voters are set to consider a November ballot question that would only allow Scott’s brother Shawn to build a casino in York County.

Commission staffers hope to conclude the initial investigation by November.