— A national media outlet raised fresh questions Tuesday about U.S. Sen. Richard Burr's stock market dealings.

Burr, already facing investigation for selloffs ahead of the COVID-19 market crash, sold his stake in a Dutch fertilizer company in 2018.

The company had been positioned to benefit from expected sanctions on Iranian oil, ProPublica reported, but the Trump administration waived some of those sanctions.

Burr and his wife sold their shares in OCI over three days in September 2018, when the shares were near their highest point in four years, ProPublica reported, relying on transaction reports that members of Congress are required to file.

The investigative journalism outfit said the Burrs had 1,400 shares with peak value of about $47,670 and reported that, a month after the sales, OCI shares began a dramatic fall.

OCI trades on the Euronext market in Amsterdam. It produces nitrogen fertilizers and industrial chemicals, and the Trump administration's November 2018 decision to waive some Iranian restrictions "undercut the company’s hopes," ProPublica reported. That month, the company also failed to meet earnings projections.

Burr's office declined Wednesday to comment on the new reporting. He also declined to discuss it with ProPublica.

The outlet noted Burr's roles in the U.S. Senate as chairman of the Intelligence Committee and as a member of Senate Finance, which give him some oversight on Iran issues. But ProPublica said it had no evidence Burr knew in advance about the Trump administration's sanction waivers.

It was ProPublica that broke the news last month that Burr sold off between $628,000 and $1.72 million in stock – required disclosures make it difficult to nail down values – shortly before the market crashed. Other outlets have since reported that the U.S. Department of Justice is probing the trades.

Burr said in a statement at the time that he relied only on publicly available information to make the trades, and he asked the Senate Ethics Committee to investigate in a spirit of transparency.

His office has declined to provide WRAL News with whatever documentation it forwarded to the committee for that investigation or to say whether he's heard from investigators with the Department of Justice or the Securities and Exchange Commission.

An investor in Wyndham Hotels, one of the stocks Burr sold off, has accused the senator of insider trading in a federal lawsuit.