Barack Obama's presidential campaign has been fined $375,000 by the Federal Election Commission for violating federal disclosure laws, Politico reports.

An FEC audit of Obama for America's 2008 records found the committee failed to disclose millions of dollars in contributions and dragged its feet in refunding millions more in excess contributions.

The resulting fine, one of the largest ever handed down by the FEC, is the result of a failure to disclose or improperly disclosing thousands of contributions to Obama for America during the then-senator's 2008 presidential run, documents show.

The FEC says the Obama campaign failed to disclose the sources of 1,300 large donations, which together accounted for nearly $1.9 million. Election Commission rules state campaigns must report donations of $1,000 or more within 20 days of Election Day.

Obama for America was also fined for "untimely resolution of excessive contributions," according to the conciliation agreement, FEC says. The campaign accepted more than $1.3 million in contributions that came from donors who had already given $46,000—the maximum allowed by FEC rules. The campaign eventually refunded the excess cash but did not do so within the 60-day window allotted for resolving such cases, FEC said.

In addition to failing to report big donors and excess donations in a timely manner, the Obama campaign incorrectly dated the filings dealing with $85 million in funds, the FEC claims. This error appears to have been primarily the result of one transfer to the campaign committee from the Obama Victory Fund, a fundraising group that includes money raised by the Democratic National Committee that is earmarked for the presidential race.

The fines were a result of complaints filed with the FEC by the Republican National Committee. The Obama campaign has been quick to point out that the errors constitute a small portion of the more than $750 million it raised during the 2008 election cycle.

"The 2008 campaign was a record breaking campaign with over 3 million grassroots donors," Obama for America spokeswoman Katie Hogan said in an email to U.S. News. "The very few outstanding questions have now all been resolved."

The results of the audit were released in April of 2012, but the letter detailing the fines the FEC planned to levy was not sent until December.