WASHINGTON--The Justice Department late Wednesday lifted a gag order on an FBI informant to provide testimony to Congress about an inquiry linked to a 2010 deal that transferred ownership of uranium mining firm to a Russian-owned company.

The action comes a day after California Rep. Devin Nunes, the Republican chairman of the House Intelligence Committee, announced an investigation into the matter and any role then-Secretary of State Hillary Clinton played in the deal.

"As of tonight, the Department of Justice has authorized the informant to disclose to the chairmen and ranking members of the Senate Committee on the Judiciary, the House Committee on Oversight and Government Reform, and the House Permanent Select Committee on Intelligence, as well as one member of each of their staffs, any information or documents he has concerning alleged corruption or bribery involving transactions in the uranium market," Justice spokesman Ian Prior said.

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President Trump and some Republican lawmakers have been pressing the matter, alleging that the deal involved Russian donations to the Clinton foundation, a charge the Clintons have long rejected.

Iowa Sen. Charles Grassley, the Republican chairman of the Senate Judiciary Committee had called on the Justice Department to lift the non-disclosure agreement, clearing the way for the informant, who has not been publicly identified, from speaking to Congress.

"The executive branch does not have the authority to use non-disclosure agreements to avoid congressional scrutiny," Grassley said in a recent letter to the Justice Department.