Oliver Schwab, Arizona Rep. David Schweikert’s chief of staff, resigned as they both face an investigation by the House Ethics Committee. 

Schwab announced his resignation Monday, saying he was having surgery and will work as a U.S. Coast Guard licensed maritime captain, AZ Central reported. 

Schwab and Schweikert are under investigation by the Ethics Committee since Schwab was allegedly paid by Schweikert’s campaign beyond the limit allowed for outside earned income for congressional staffers.

The Ethics Committee voted unanimously since it appeared that Schwab’s consulting firm, Chartwell Associates, received $148,315 in consulting fees and $57,946 in travel fees since 2014.

Schwab told the Washington Examiner in 2017 that he was a one-man shop but denied wrongdoing.

Schwab later repaid Schweikert’s campaign committees last year $50,372 as a “repayment of erroneous reimbursements.”

Schweikert announced Katherina Dimenstein would replace Schwab. Dimenstein served as Schweikert’s legislative director and was a policy adviser to Sen. Joni Ernst.

“Katherina Dimenstein is one of the most brilliant policy minds I have ever worked with,” the senator said in a statement. 

Schweikert also praised Schwab, who worked with him since 2011.

“Oliver is the best I have ever seen at helping people work through their needs,” he said in a statement. “I am extremely grateful for the near decade that Oliver has devoted to serving Arizona.”