The Colorado Secretary of State's office has given the initial go-ahead for an investigation into a campaign finance complaint alleging Google co-founder Sergey Brin's charitable foundation made a dark money campaign finance donation supporting a ballot initiative that would have greatly restricted new oil and gas drilling in that state.

The complaint filed by a former Republican staffer alleges Brin's foundation made a campaign donation to Colorado Rising, a political issue committee supporting Prop 112, which asked voters to approve significantly greater setback distances that new oil and gas rigs would have to be placed from "vulnerable" infrastructure such as schools and hospitals.

Opponents of the measure argued the setbacks were so great and the definition of vulnerable so vague that the law would have amounted to a de facto ban, and voters turned the measure down.

As a tax-exempt foundation, the Brin Family Foundation would be prohibited from political contributions. But the complaint deals less with the IRS implications and instead focuses on possible violations of Colorado campaign finance law.

The complaint cited numerous subsequent amended campaign finance filings in which the donation was moved away from Colorado Rising and over to ProgressNow Colorado, a nonprofit.

The attorney for the complainant, former secretary of state Scott Gessler, told the Washington Free Beacon the initial filing and the subsequent corrections were attempts "to cover up the original contribution and protect the Brin Foundation."

The complaint also alleges that by using the money in support of Prop 112, ProgressNow Colorado should have registered as an issue committee.

If those allegations pan out, it could mean fines for ProgressNow Colorado, one of the leading leftwing elements in the swing state. It might also mean it could be required to make additional disclosures of money it received and spent last cycle, something it would ordinarily be able to avoid as a nonprofit.

In a "Notice of Initial Review" finding published late Wednesday, the secretary's office found the complaint had "alleged sufficient facts to support a legal and factual basis" and will therefore conduct an "additional review of the alleged violations."

Gessler applauded the decision while adding a cautionary tone.

"We gave investigators a very good road map and money trail to follow, so they'll have no excuses if they drop the ball or duck for political cover as the probe unfolds," Gessler said about the developments in a press release. "This would have been a tough one for the new secretary of state to ignore, given her vocal opposition to ‘dark money' in Colorado politics, but these allegations involve her political allies, so the process will have to be carefully watched going forward."

Secretary of State Jena Griswold, a Democrat, took office last month, and made "secret political spending" a strong part of a published policy agenda in order to "put our democracy back in the hands of everyday Coloradans."

"We will work to shine light on secret political spending through stronger disclosure, by addressing coordination between candidates and special interests, and by strengthening our enforcement and oversight of all who engage in political activity in our state," Griswold wrote.

The attorney for Colorado Rising, Martha Tierney, did not respond to requests for comment from the Free Beacon, but told the Denver Post, "They make a whole bunch of suppositions that are not true. And when the facts are known, I'm confident the complaint will be dismissed."

ProgressNow Colorado and Pacific Management Services, the company that manages the Brin Family Foundation, did not return a Free Beacon request for comment.