A conservative women’s political group trying to bridge the gender gap is being accused by a progressive group of breaking federal election law, NBC News has learned.

The Independent Women's Voice describes itself as a "nonpartisan, nonprofit organization that supports women and families by providing women with fact-based evidence showing how conservative free market solutions advance prosperity, freedom, and greater choices." This election cycle, IWV has been suggesting that Clinton's policies are worse than Trump being accused of sexual misconduct and praising Trump's childcare plan.

The Center for Media and Democracy, a liberal watchdog group, told NBC News it has filed a Federal Election Commission complaint, requesting an investigation of the Independent Women’s Voice for what it says could be violations of federal law.

"What you have here is a group that claims to be nonpartisan and independent and focused on women’s issues, issues of interest to moderate women that is, in fact, heavily political and spends millions of dollars to elect some pretty extreme Republicans," Arn Pearson, the group's general counsel, told NBC News.

The complaint says the group "has reason to believe that IWV has raised and spent millions of dollars to influence the 2010, 2012, and 2014 federal elections without registering as a political committee," as required by law. It alleges that IWV spent $250,000 on behalf of Scott Brown's Senate campaign in 2010, but "has failed to report independent expenditures to the Commission, even under the minimal requirements for persons other than political committees."

Registering as a political committee requires a significantly higher level of disclosure, including the names of all donors above $200.

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"IWV has not received any complaint, and IWV has and does fully comply with all FEC and IRS rules and regulations,” Charlie Spies, counsel for Independent Women’s Voice, told NBC News.

Donald Trump's campaign manager, Kellyanne Conway, is currently listed as on temporary leave from the board of what the IWV calls "its sister organization," the Independent Women’s Forum, which is not named in the complaint.

The CMD complaint also cites a presentation the group's president, Heather Higgins, gave to activists and donors in November 2015. "For the last 5 years I have been working to provide the margin that matters in races that are toss-ups or worse," she said. "We have had a strong of wins because when we look at these things we try to think, how do you play chess rather than playing checkers?"

Two experts in campaign finance law reviewed the complaint at the request of NBC News.

"The Center for Media and Democracy makes a compelling case to at the very least open an investigation into the IWV to determine whether it violated federal campaign laws," Paul S. Ryan, vice president of policy and litigation at Common Cause, told NBC News.

But Ryan and Jessica Levinson, a professor of election law at Loyola Law School, agreed that it was unlikely the FEC would take any investigative action in response. Its own commissioners, split evenly along ideological and partisan lines, call the agency broken.

"The FEC is deadlocked, so in order to have an investigation, you need someone to break ranks. Past history indicates that's not going to happen," said Levinson.

Even if they were to open an investigation, the current Supreme Court standard on what separates a political committee from a nonprofit group advocating for an issue is a matter of fierce dispute. While current law seeks to draw a line between the two types of activities — defining a political committee as one whose "major purpose" is to sway elections — the court itself has cited the assertion that “what separates issue advocacy and political advocacy is a line in the sand drawn on a windy day."

Ryan said the court's 2010 decision in Citizens United "opened up the floodgates for corporations, including nonprofit corporations, to get involved in elections. We expected the money would flow through dark money groups like Independent Women’s Voice. It in fact has turned out that way. We’ve seen a massive increase in spending by 501c4s, so-called social welfare groups that don’t have to say where they get their money."

Levinson called the loose rules around nonprofit spending "a cloaking device for money in our political system" that helped politicians evade accountability and mislead voters. "The people are entitled to know who is trying to sway their votes," she said.