MONTGOMERY, Ala. - A complaint filed Monday accuses a super PAC that spent millions of dollars to support Doug Jones in Alabama's U.S. Senate race of breaking campaign finance law by failing to disclose donors until after the election.

The complaint against Highway 31 political action committee was filed with the Federal Election Commission by the Washington D.C.-based Campaign Legal Center. The complaint alleges the PAC used lines of credit from vendors to avoid disclosing that it was backed by well-funded national Democratic groups.

"It appears Highway 31 and its lawyers cooked up a scheme to keep voters in the dark until after Election Day about who was trying to influence their vote," spokesman Brendan Fischer told The Associated Press.

Highway 31 spent $4 million in the 2017 special election where Jones, a Democrat, defeated Republican Roy Moore whose candidacy was bogged down by allegations of sexual misconduct. It was disclosed after the election that the PAC received more than $3 million from the Senate Majority PAC, which works to elect Democrats to the U.S. Senate and $910,000 from Priorities USA.

Highway 31 has maintained it fulfilled all reporting requirements. Adam Muhlendorf, a spokesman for Highway 31, on Monday dismissed the complaint as frivolous.

"This is yet another frivolous complaint. Highway 31 has closed its books," Muhlendorf said.

Highway 31, named after a roadway crossing much of the state, emerged as a major player in the Alabama election. Many of its advertisements and mailers focused on accusations against Moore of sexual misconduct involving teenage girls decades ago. He denied the misconduct accusations.

The complaint said that Highway 31 soon after forming got a line of credit from out-of state vendors to avoid having to report donors, and speculated that Senate Majority PAC, or others, guaranteed that the vendors would get paid.

"It is hard to believe that the vendors here would, in the ordinary course of business, extend hundreds of thousands of dollars in credit to an entity that was formed just weeks earlier and had a total of $0 in its bank account," the complaint read.

Fischer said he was concerned that, if not stopped, it would create a new "loophole" that would be widely replicated by groups on both sides of the political aisle.

The complaint also said that the PAC reported a contribution from Priorities USA Action that the group did not report making.

Muhlendorf said that was a "minor inaccuracy that will be corrected."

News from © The Associated Press, 2018