The Maine state ethics board on Wednesday voted unanimously to impose a record fine against the National Organization for Marriage (NOM) for violating Maine's donor disclosure law.

In imposing the hefty fine, the committee accepted the recommendation of the Maine Commission on Governmental Ethics and Election Practices, which determined that NOM attempted to conceal its donor list during the 2009 people's veto campaign that repealed a gay marriage law approved by lawmakers. Three years later, voters reversed course, making Maine the first state in the nation to legalize such unions at the ballot box.

The board imposed a record $50,250 fine against NOM, the Kennebec Journal reported. The organization vowed to appeal the ruling, saying it would not disclose its donors list. It said doing so would put individuals at risk of threats and harassment.

NOM contributed more than $2 million to the $3 million campaign to uproot the marriage law. The referendum campaign was led by Stand for Marriage Maine, a Maine-based ballot question committee. NOM has argued that it donated money to the committee from a general fund.

However, NOM President Brian Brown was an operating officer at Stand for Marriage Maine.

“I have a hard time not concluding that you didn't control the ballot question committee,” said Michael Healy, a member of the ethics committee.

The complaint against NOM, filed by Rights Equal Rights President Fred Karger, states that under Maine election laws, NOM should have registered as a ballot committee. Such groups are required to report contributions and expenditures to the state.

“After nearly five years of NOM head Brian Brown and his army of lawyers fighting in state and federal court against the investigation, the verdict is in and NOM is guilty of election fraud,” Karger said in a written statement. “All Americans who believe in truth and transparency in our election process owe everyone in Maine who worked on this investigation and all the lawsuits around it a huge debt of gratitude.”

NOM has repeatedly asserted that it must protect the identities of its donors.