Sen. Richard Burr of North Carolina and his brother-in-law, who is chairman of an independent federal agency, spoke on the phone shortly before both men sold off stocks weeks ahead of national Covid lockdowns in 2020, the Securities and Exchange Commission said in a court filing.

The filing comes as the SEC continues to investigate whether Burr, a Republican, and his brother-in-law Gerald Fauth sold the stocks on the basis of nonmaterial information that Burr obtained as part of his job.

Members of Congress are barred from trading nonpublic information they receive as a result of their positions as lawmakers.

Fauth is chairman of the National Mediation Board, an agency that facilitates labor-management relations in the U.S. railroad and airline industries. He also is “the brother of Senator Burr’s wife, Brooke Burr,” the SEC filing notes.

The SEC’s probe is focused on the timing of trades in February 2020, after Burr and other lawmakers were briefed on the danger of the coronavirus pandemic spreading to the United States.

A week after the stock sales by Burr and his brother-in-law, stock markets began plunging over fear that the pandemic would cripple the global economy. The Dow Jones Industrial Average lost 30% of its value in the weeks following Burr’s trades.

Burr in March 2020 said, “I relied solely on public news reports to guide my decision regarding the sale of stocks.” He added: “Specifically, I closely followed CNBC’s daily health and science reporting out of its Asia bureaus at the time.”

The FBI seized Burr’s phone in May 2020 as part of a criminal probe of the trades. That move led Burr to step aside as chairman of the Senate Intelligence Committee. On Jan. 19, the day before Joe Biden was inaugurated as president, Burr announced that the Justice Department had informed him that it closed its investigation without lodging criminal charges against him.

The SEC, whose probe is civil in nature, said in a new filing that Burr, at 8:45 a.m. on Feb. 13, 2020, called his broker to sell more than $1.65 million worth of stock, “all but one of the equities in his and his wife’s joint individual retirement account … portfolio.”

At 11:32 a.m. that day, Burr called his Fauth’s cellphone, according to the filing in U.S. District Court in Manhattan. “The call lasted 50 seconds.”

At 11:33 a.m,. a minute or less later, Fauth, the chairman of the National Mediation Board, called his primary stock broker’s landline, the SEC said.

After failing to reach his first broker, Fauth called a second broker within two minutes and “directed her to sell several stocks in his wife’s account,” the filing reveals.

Fauth “sold between $97,000 and $280,000 worth of shares in six companies — including several that were hit particularly hard in the market swoon and economic downturn,” according to ProPublica, which first reported the court filing.

Minutes after that, following Burr’s own instructions from earlier that morning, the senator’s broker “entered trades to sell equities in the IRA accounts of both Senator Burr and his wife,” according to the filing.

The SEC’s filing seeks a judge’s order that would force Fauth to comply with an investigative subpoena that was issued in March 2020. The subpoena seeks documents, other evidence and Fauth’s testimony.

Fauth and his lawyers have stonewalled that subpoena, the filing indicates.

The SEC said in its filing that, “Among other things, the Commission is investigating whether Senator Richard Burr … sold stocks on the basis of material nonpublic information on February 13, 2020, in violating of the federal securities laws, including the STOCK Act, a statute passed by the U.S. Congress in 2012 to prohibit its members from using nonpublic information derived from their positions for the personal benefit.”

“The Commission is also investigating whether [Fauth] and his wife, Mary Fauth, sold securities on the same day on the basis of material nonpublic information supplied to them by Senator Burr in violation of his duties.”

A spokesman for Burr and a lawyer for Fauth did not immediately respond to requests for comment.