Mainers deserve to know who’s trying to influence their elections, and it’s becoming clear that Horseracing Jobs Fairness — the secretive referendum campaign to open a casino in southern Maine—– won’t come clean without significant pressure.

The referendum, which is likely to go before voters in November, is written to allow only one man — Shawn Scott — to build a casino in an undetermined location in York County. His sister, Lisa Scott, who has been the public face of the campaign, and three ballot question committees connected to her have all filed late or inaccurate financial disclosure reports, according to Ethics Commission staff. Commissioners are slated to take up the issue at a meeting Friday; commission staff want them to authorize further investigation into the referendum effort.

If there’s anyone who deserves closer scrutiny, it’s the Horseracing Jobs Fairness campaign. They’ve shown that they won’t open up unless someone is leaning on them.

Case in point: When the ballot question committee came together in late 2015, they said that Lisa Scott herself was bankrolling the effort. But it wasn’t until April of this year that Scott disclosed that the $4.3 million spent on the campaign’s petition drives came from a Japanese consulting company and an offshore investment firm. And that disclosure was prompted by an ethics commission order.

Although Shawn Scott has been dogged by lawsuits and allegations of fraud, he’s a major gambling industry player who’s taken home big paychecks through his casino investments around the country — like the $30 million he pocketed after selling a Bangor racetrack and the rights to operate a casino there, which he’d bought for $2.5 million.

The Scott siblings haven’t been deterred by the concerns raised about their latest Maine initiative. They continued to push for signatures after their first, failed drive, in which petition circulators were accused of aggressive and misleading tactics.

And Lisa Scott has said that the problems with her finance filings were an honest mistake and that her family is committed “to bringing tens of millions of dollars in new revenues for education, health care and the horse-racing industry, as well as nearly a thousand new jobs to Maine.” We’re not as sure as she is that the York County casino is going to benefit anybody but Shawn Scott — and that’s why Maine should put the campaign under the microscope.