The Minnesota Campaign Finance and Election Board is proceeding with an investigation of a group backing that state’s anti–marriage equality constitutional investment.

The Human Rights Campaign, which had pushed for the investigation of Minnesota for Marriage, reported Friday that it is going forward. Common Cause of Minnesota filed a complaint last month against Minnesota for Marriage and the Minnesota Family Council, saying they had violated state campaign finance laws by failing to disclose individual donors.

Minnesota for Marriage was cofounded by the antigay National Organization for Marriage to work for the amendment, which will go before voters in November. According to HRC, Minnesota for Marriage reported raising $1.2 million last year but identified only seven individual donors, responsible for just $2,000 of the total, even though it had apparently solicited contributions several times. Three organizations were identified as donors — NOM, the Minnesota Family Council, and the Minnesota Catholic Conference. Minnesotans for All Families, the group working to defeat the amendment, reported 773 individual donors in the same period.

“NOM and its allies have deliberately evaded Minnesota’s public disclosure laws,” said HRC president Joe Solmonese in a news release. “It’s time they be held to account for repeatedly playing fast and loose with campaign finance laws.” He further called on the election board “to rebuff any political pressure to water down this investigation.”