BOISE (KTVB) -- Federal election regulators have sent former U.S. Sen. Larry Craig a warning letter that he failed to submit financial disclosure documents.

The Federal Election Commission says Craig failed to report his April quarterly finances.

Craig told The Associated Press that he submitted the report Monday.

The Idaho Republican says he has continued to file quarterly reports - despite leaving office in 2009 - because of his legal battles over his use of campaign funds.

Most recently, a federal judge ordered him to pay nearly $242,000 to the U.S. Treasury for improperly using campaign funds to cover legal expenses involving a 2007 airport bathroom sex sting.

Craig was arrested after being accused of soliciting sex in a men's bathroom at the Minneapolis-St. Paul International Airport by an undercover officer.