While the media’s attention has shifted to the indictment of Paul Manafort, the Obama administration’s handling of the Uranium One “bribery plot” (as The Hill called it in a startling expose) raises serious, critical questions that must be answered about the Justice Department’s handling of the investigation.

These questions can only be answered if Congress fulfills its oversight obligation by conducting an intense, serious investigation, and if the current leadership in the Justice Department cooperates by providing all of the information needed to fully explain what happened, and doesn’t try to obstruct the investigation.

First, a short timeline.

According to The Hill, the FBI gathered substantial evidence in 2009 (when the bureau was under the direction of Robert Mueller) that officials in the Russian nuclear industry were using bribery, kickbacks, extortion, and money laundering to grow its “atomic energy business inside the United States.”

That included routing “millions of dollars to the U.S. designed to benefit former President Bill Clinton’s charitable foundation during the time Secretary of State Hillary Clinton” served on the federal government’s Committee on Foreign Investments.

In 2010, that committee, which consists of representatives from 14 U.S. government agencies and included Hillary Clinton and then-Attorney General Eric Holder, approved the purchase by the Russians of the Uranium One mining company, giving them control of about 20 percent of U.S. uranium production.

In 2011, the same committee approved the sale of commercial uranium to U.S. nuclear power plants by Tenex, a subsidiary of Rosatom, a Russian nuclear company controlled by the Russian government.

This sale to a hostile foreign government occurred despite the fact that the U.S. only produces about one-fifth of the uranium it needs for its nuclear plants, which in turn produce one-fifth of the country’s power generation needs.

The FBI even had a U.S. businessman as an informant who was making kickback payments (with the permission of the FBI) at the direction of Vadim Mikerin, the key Russian official overseeing the expansion of the Russian nuclear industry into the U.S. through Rosatom.

The first kickback payment, according to the FBI, was in November 2009. The bribes and kickbacks also involved an American uranium-trucking firm. The FBI imposed a nondisclosure agreement on the informant that was only recently voided by the FBI after Congress sought his testimony.

Yet none of the evidence that the FBI had about this “racketeering scheme”—which is what it was called in an affidavit by an Energy Department agent assigned to assist the FBI in the case—was brought to the attention of the Committee on Foreign Investment in 2010 or 2011 by Holder.

Recall that as attorney general, Holder was responsible for overseeing the FBI and its investigations.

None of the information about the millions of dollars being routed to the Clinton Foundation was brought to the attention of the committee by Hillary Clinton. And no congressional intelligence committees were briefed about it either, according to The Hill’s story.

Mikerin was not indicted until 2014, along with several executives from the trucking firm. Mikerin was only charged with a single count of money laundering, not with paying multiple bribes or soliciting multiple kickbacks.

A plea deal was reached in 2015 and made public through a press release in August of that year. The plea agreement cited only transactions that occurred in 2011 and 2012 after the Committee on Foreign Investment’s approval of the Russian uranium sales, despite the fact that the corruption had started in 2004.

The final court case, according to The Hill, “made no mention of any connection to the influence peddling conversations the FBI undercover informant witnessed about the Russian nuclear officials trying to ingratiate themselves with the Clintons even though agents had gathered documents showing the transmission of millions of dollars from Russia’s nuclear industry to an American entity that had provided assistance to Bill Clinton’s foundation.”

This summary of the case raises important questions:

Why didn’t Holder or Mueller brief the Committee on Foreign Investment about the bribery and kickbacks being engineered by Rosatom when it was seeking approval of its purchase of Uranium One in 2010 or its sale of uranium to American nuclear plants by Tenex in 2011? Why weren’t the House or Senate intelligence committees informed? The FBI and the Justice Department already had their informant in place in 2009 and already had evidence of the corruption. Why was the indictment and prosecution of Mikerin delayed, and why did the Justice Department allow this racketeering enterprise that corrupted the American uranium industry to continue for five years? Why were the possible charges against Mikerin reduced? Why was the evidence of attempted influence peddling suppressed and not made a part of the prosecution or mentioned in the plea agreement? Why did the FBI force a nondisclosure agreement on its informant, particularly because it was apparently the informant that first contacted the FBI to tell it what was going on? Who was the lawyer at the Justice Department who made this decision? And if the Justice Department can provide some law enforcement justification for it, why did it extend beyond the end of the case?

If a law enforcement investigation is ongoing, a nondisclosure agreement might be justified to prevent the informant from publicizing the investigation and sabotaging the prosecution. But this case was over in 2015—there is no evidence of any ongoing investigation beyond that date.

Without a credible explanation, it is hard to come to any conclusion other than it was a political decision intended to cover up what happened.

Who can answer all of these questions? That would be Holder, Mueller, and the other federal officials involved in the case.

The Justice Department has already made the right decision about the informant. On Oct. 25, it released him from the gag order and told him he could testify before Congress. Now, the Justice Department needs to turn over its complete file on the investigation and prosecution.

The bottom line question that needs to be answered is this: Why did the Obama administration approve the transfer of 20 percent of America’s uranium industry to a company owned by the government of a hostile country headed by a dictator when our Justice Department and our FBI knew that government had engaged in a corrupt, criminal conspiracy to get that foothold in America?

It is up to Congress to find out.