WASHINGTON (AP) — The Justice Department filed a lawsuit Thursday against Donald Trump's former campaign chairman Paul Manafort — who was convicted in special counsel Robert Mueller's Russia investigation and later pardoned — seeking to recover nearly $3 million from undeclared foreign bank accounts.

The lawsuit, filed in federal court in West Palm Beach, asks a judge to force Manafort to pay fines, penalties and interest after prosecutors say he failed to disclose more than 20 offshore bank accounts he ordered opened in the United Kingdom, Cyprus, St. Vincent and the Grenadines.

The Justice Department alleges Manafort failed to file federal tax documents detailing the accounts and failed to disclose the money on his income tax returns. The lawsuit charges the money was related to consulting work in Ukraine with his deputy Rick Gates and an associate, Konstantin Kilimnik, who were both key figures in Mueller's investigation.

In court documents, the Justice Department alleges Manafort "knowingly, intentionally, and willfully filed and conspired to file false tax returns from 2006-2015 in that he said he did not have reportable foreign bank accounts when he knew that he did." The suit says the Treasury Department notified Manafort of the fines and assessment in July 2020.

Manafort's lawyer, Jeffrey Neiman, argues the suit is being filed "for simply failing to file a tax form."

"Mr. Manafort was aware the Government was going to file the suit because he has tried for months to resolve this civil matter," Neiman said in a statement. "Nonetheless, the Government insisted on filing this suit simply to embarrass Mr. Manafort."

Manafort, who led Trump's campaign during a pivotal period in 2016 before being ousted over his ties to Ukraine, was among the first people charged as part of Mueller's investigation into ties between the Trump campaign and Russia. He was later sentenced to more than seven years in prison for financial crimes related to his political consulting work in Ukraine. Trump pardoned him in December 2020.

Though the charges against Manafort did not concern the central crux of Mueller's mandate — whether the Trump campaign and Russia colluded to tip the election — he was nonetheless a pivotal figure in the probe that shadowed Trump's presidency for years.

His close relationship to Kilimnik, whom U.S. officials have linked to Russian intelligence, and with whom he shared internal Trump campaign polling data, attracted particular scrutiny during the investigation, though Mueller never charged Manafort or any other Trump associate with conspiring with Russia.

Despite the pardon, the government believes Manafort still owes the money for the alleged financial misconduct.