Rep. Tom Malinowski, D-N.J., is taking heat from two separate watchdog groups after he failed to publicly disclose at least $671,000 in personal stock trades in 2020.

On Monday, the nonpartisan Campaign Legal Center sent a letter to the head of the Office of Congressional Ethics demanding an investigation, and the conservative-leaning Foundation for Accountability and Public Trust filed a complaint with the Office of Congressional Ethics.

"The STOCK Act requires accountability for any member of Congress who fails to report stock trades within 45 days of the transaction," the Campaign Legal Center said in the letter. "Rep. Malinowski repeatedly failed to comply with this requirement for over two years."

Representative-elect Tom Malinowski, a Democrat from New Jersey, speaks during a news conference on Capitol Hill in Washington, D.C., U.S., on Friday, Nov, 30, 2018. Photographer: Andrew Harrer/Bloomberg via Getty Images

The Foundation for Accountability and Public Trust called Malinowski's actions "unacceptable."

"The law is abundantly clear on what is required of all House Members when it comes to personal financial disclosures. Rep. Malinowski’s failure to report roughly 90 financial transactions is unacceptable. More egregious is that many of the transactions involved COVID-related stocks," Kendra Arnold, executive director of the Foundation for Accountability and Public Trust, said in a statement.

Malinowski made a flurry of trades in March 2020 at the beginning of the coronavirus pandemic, investing in General Mills, the J.M. Smucker Company and, later, Peloton, according to Business Insider, which first reported Malinowski's failure to disclose the trades.