TOPEKA, Kan. (AP) — The Federal Election Commission is examining now-refunded campaign contributions that Kansas Rep. Steve Watkins’ father funneled through the freshman Republican congressman’s sisters and others during the 2018 campaign.

Topeka physician Steven Watkins Sr. confirmed Friday that the FEC is looking into thousands of dollars he steered into his son’s campaign through other donors, including his daughters and a homebuilder, The Kansas City Star reported. He first confirmed the inquiry for Politico.

It's another legal headache for the congressman in eastern Kansas' 2nd District as he faces a GOP primary challenge from State Treasurer Jake LaTurner. The younger Watkins has been under investigation by local officials over whether he violated state election laws for previously listing a UPS Inc. store as his residence.

Some Republicans want to oust Rep. Watkins, and former GOP Gov. Jeff Colyer publicly encouraged LaTurner to run. Watkins emerged from a crowded 2018 primary race with less than 27% of the vote and won the November election by less than a percentage point.

Watkins Sr. told The Star that any violations of federal campaign finance laws on his part were inadvertent and, “I had no idea that was improper."

“They’re just evaluating the voluntary report that we submitted after we found out that what I did was wrong,” Watkins Sr. said.

Watkins Sr. said he self-reported the errors and the FEC hasn’t given him any indication of when it might conclude the matter. He said he did not coordinate with his son’s campaign and emphasized that the donations were refunded.

Jim Joice, a spokesman for Rep. Watkins, said neither the congressman “nor his campaign committee are under FEC investigation.”

A FEC spokeswoman said it is prohibited from disclosing information about enforcement matters.

Watkins’ 2018 campaign refunded $36,000 in donations, including a $10,800 contribution from Dennis Sumner Construction Company in Topeka. The campaign also returned donations from Sumner and Kathryn Sumner, who lives at the same address, and Diane Watkins.

The donations are a small fraction of Watkins Sr.’s investment in the 2018 race. He put $765,000 into the Kansans Can Do Anything PAC, an entity he set up to support his son’s candidacy.

Meanwhile, the Shawnee County sheriff's office has completed the first part of its investigation into whether the congressman broke state election laws.

Sarah Powell, a spokeswoman for Shawnee County District Attorney Mike Kagay, said Friday that the sheriff’s office is following up on additional questions before Kagay makes a decision on whether to charge Watkins with a crime.

Rep. Watkins listed a box at the UPS Store as his residential address in November, when he cast a ballot in a Topeka City Council race. In December, he changed his residential address on a voter registration form to a Topeka apartment complex about 2 miles to the north — outside the City Council district.

He filed another voter registration form in late January listing a new address at the same complex. He'd previously listed the address for the complex's office.

Questions about his actions prompted Americans For Public Trust to file a complaint against Watkins with the Office of Congressional Ethics. The group, which launched last year, is officially nonpartisan but its staff is primarily Republican.

Joice said Watkins will continue focusing on "standing with President Trump, defending conservative values, and battling the political swamp.”