PORTLAND, Maine — A former Portland real estate developer waived indictment and pleaded guilty Monday in U.S. District Court to making $22,500 in illegal campaign contributions to presidential candidates during the 2011 primaries, according to the U.S. attorney’s office.

Michael A. Liberty, 56, now of Windermere, Florida, admitted that between May and June 2011, he made campaign contributions through nine employees, associates and family members to the principal campaign committee of a candidate for president, a press release issued Monday said.

The case appears to be the first time anyone has been prosecuted in Maine for violating the Federal Election Campaign Act.

“Mr. Liberty has cooperated with the government in this matter, which involves incidents that occurred six years ago,” his attorney, Richard Zack of Philadelphia, said Monday afternoon. “He has accepted responsibility for his conduct and wishes to move on with his life.”

Zack and Assistant U.S. Attorney Donald Clark, who is prosecuting the case, refused to name which campaign received the illegal contributions.

Court documents also do not name the candidate, but in May 2011, Liberty contributed $2,500 to Mitt Romney’s campaign for the GOP nomination for president, according to the Center for Responsive Politics.

Campaign finance laws limit individual contributions to a candidate to $2,500 during the primary election cycle.

Clark declined to comment on the case. It is the practice of the U.S. attorney’s office not to comment on cases until after sentencing.

Liberty remains free on personal recognizance bail. Conditions include his not traveling outside the state of Florida without prior permission from an officer with U.S. Probation and Pretrial Services in Orlando, Florida.

Under the federal sentencing guideline range the recommended prison sentence would be between six and 12 months, according to the plea agreement. The prosecution agreed to recommend a sentence at the low end of the guideline range.

Liberty faces a fine of between $67,000 and $250,000, the plea agreement said. A sentencing date has not been set but is not expected to take place until next year.

In addition to his activity in presidential races, Liberty has focused on elections in Maine, often in support of conservative candidates. In 2014, he was the primary supporter of the Citizens for a Safe Cumberland County Political Action Committee, which spent $100,000 on behalf of Michael Edes, who was a candidate for Cumberland County sheriff. According to a 2014 article in the Portland Press Herald, Edes was accused of coordinating with Liberty’s PAC, but the Maine Commission on Governmental Ethics and Election practices found no evidence to justify an investigation.

Besides contributing to Romney, Liberty also has made campaign donations to Tim Pawlenty, Bob Dole, George H.W. Bush, Bruce Poliquin, the Maine Republican Party, Olympia Snowe, the Republican National Committee and others. He also supported some Democrats over the years, including George Mitchell, Ethan Strimling, John Baldacci and Joe Brennan.

At one point, according to a friendly 1989 profile in Yankee Magazine posted on Liberty’s website, Liberty was worth more than $300 million, money he made in real estate and investments. Among his many holdings over the years was Oxford Plains Speedway, and he has been more recently rumored to have shown interest in Scarborough Downs, which is for sale.

BDN writer Christopher Cousins contributed to this report.