(Bloomberg) -- The Securities and Exchange Commission is seeking to force U.S. Senator Richard Burr’s brother-in-law to testify about their stock sales just before the beginning of the coronavirus pandemic, according to court records.

Gerald Fauth has “waged a relentless battle” to avoid complying with a subpoena issued to him in May of 2020, the SEC said in court filings. “The Commission is investigating possible insider trading by Fauth’s brother-in-law, Senator Richard M. Burr, and respondent’s own sales of stock in the minutes after speaking with Senator Burr on the day the senator sold the vast majority of his own portfolio.”

Fauth, a holdover Donald Trump appointee to the National Mediation Board, which governs labor relations in the rail and airline industries, has said he’s too ill to answer questions from investigators.

A Manhattan federal judge has set a hearing for Friday on the agency’s request for an order compelling Fauth’s testimony.

Burr, a North Carolina Republican, liquidated holdings after receiving briefings about the spreading coronavirus in his then-role as chair of the Senate Intelligence Committee. He maintained the sales were unrelated to the information he received. The Justice Department closed a related criminal inquiry earlier this year. 

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