WASHINGTON – A conservative watchdog group filed an ethics complaint against U.S. Rep. John Lewis Monday, alleging that the Atlanta Democrat improperly hired his top aide as a highly-paid staffer on his reelection campaign.

In a complaint filed with the Office of Congressional Ethics, the Foundation for Accountability and Civic Trust, or FACT, alleged that Michael Collins, Lewis' longtime chief of staff, broke ethics rules that bar senior staffers from serving on campaign organizations as officers and making more than the allowed amount for outside work.

FACT said Lewis was also at fault for hiring Collins as his campaign treasurer.

"Representative Lewis's dual employment of Collins as both his chief of staff and campaign treasurer indicates that both Lewis and Collins violated ethics rules prohibiting this type of employment and outside salary limits," Matthew Whitaker, the group's executive director, wrote in a letter to Congress' nonpartisan ethics watchdog on Monday.

Lewis spokeswoman Brenda Jones said lawyers have reviewed the matter "and we were assured there was no violation of ethics rules."

"Though Mr. Collins was temporarily listed as treasurer when the old treasurer had to leave the campaign, Mr. Collins never received any payment for his service as acting treasurer. Thus, it is our understanding that there was no violation of House ethics rules," Jones said in a statement.

Lewis' campaign committee paid Collins $27,550 in consulting fees in 2015, according to federal campaign finance filings.

Jones said Lewis would comply with any inquiries made by the ethics committee but sharply criticized "right wing attack dogs" for going after the 16-term congressman for his dissent against President Donald Trump.

"They have published skewed stories about his legacy, sent partisan so-called journalists to try to corner him in the halls of Congress in unauthorized spaces, and now they are filing an ethics complaint," Jones said. She added, "too often in contemporary America speaking truth to power means having to suffer threats, harassment and attempts at intimidation."

This isn't the first time FACT has gone after Lewis. The group slapped the 16-term lawmaker and several other House Democrats with another ethics complaint last summer for fundraising off the 26-hour gun control sit-in they led on the House floor.

Collins was cited by the House Ethics Committee in 2011 for failing to list $54,00 he made in consulting fees on his income tax returns and finance disclosure reports.

"These mistakes were not intentional but were due to an inadvertent omission in disclosure, " Collins said at the time. He said he accepted "full responsibility" for the omission.

This is the second time Collins has made the news over the last year. Federal prosecutors in July accused a Washington, D.C. man of posing as Collins in order to snag pro football tickets and star treatment at a South Beach bar.