A former FBI informant can now testify to Congress about the Russian nuclear industry's bribery and money laundering during the time of the Obama administration, after being released from a confidentiality agreement by the Justice Department on Wednesday.

Congressional committees have attempted to interview the unidentified informant, but were unable to because of a nondisclosure agreement he had signed with the FBI. In 2016, the Justice Department required him to withdraw a lawsuit that claimed he would raise the case during the 2016 election.

"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, including but not limited to anything related to Vadim Mikerin, Rosatom, Tenex, Uranium One, or the Clinton Foundation," Ian Prior, principal deputy director of public affairs at the Justice Department, said in a statement sent to the Washington Examiner.

The informant's identity has not been publicly disclosed because he was undercover for almost five years. During that time, he provided agents information about Russia's atomic energy business in the U.S.

Victoria Toensing, who is representing the informant, said the FBI had submitted a letter stating there was no reason for the informant's work to be kept confidential, according to The Hill. This means he is allowed to possibly testify before various committees in Congress, including the Senate Judiciary Committee, the House Intelligence Committee, and the House Oversight and Reform Committee.

"The FBI has informed me that they are releasing my client from his NDA so that he can testify to Congress about his work uncovering the Russian nuclear bribery case and the efforts he witnessed by Moscow to gain influence with the Clintons in hopes of winning favorable uranium decisions from the Obama administration," Toensing said.

"He is now able and willing to talk with the confessional committees seeking his testimony though I will be working with all parties to ensure his identity remains confidential to ensure his safety," she added.

A report from The Hill last week revealed that the FBI has evidence dating as far back as 2009 that nuclear industry officials from Russia had been involved in bribery, kickbacks, extortion, and money laundering that benefited Russian President Vladimir Putin's atomic energy project expansion with the U.S.

The report also verified that Russians sent millions of dollars to the Clinton Foundation from 2009 to 2013 while she was serving as secretary of state.