Special Counsel Robert Mueller is close to filing a fresh set of charges against the Russians who stole and leaked thousands of emails from servers belonging to Hillary Clinton’s presidential campaign and the Democratic National Committee, according to a report.

The new charges are backed up by extensive intelligence from the CIA, the FBI, the National Security Agency and the Department of Homeland Security, several current and former U.S. officials told NBC News.

News of the expected indictment comes weeks after Mueller charged 13 other Russian nationals with using social media, illegal ad-buying schemes and other complex methods to undermine American democracy and help elect Donald Trump.

Mueller has long had plenty of evidence to file charges against the Russian hackers, but has held off, citing strategic issues and timing, according to the sources. Unveiling high-profile indictments targeting foreign adversaries without first exhausting all angels could expose informants and sensitive intelligence, the sources said.

Mueller’s team probes Roger Stone, Trump’s WikiLeaks connections

The laundry list of charges reportedly being mulled by Mueller include violations of federal election laws, computer fraud, and criminal conspiracy.

A spokesman for the special counsel’s office declined to comment, citing its ongoing investigation.

The new indictments would take a deep dive into how Russian intelligence agencies hired skilled hackers to break into computer networks and steal emails from the DNC and Hillary Clinton’s campaign chairman John Podesta. They would also focus on the dissemination of those emails, which was first and foremost conducted by WikiLeaks, the self-described transparency site ran by Julian Assange.

While on the campaign trail, President Trump used to celebrate the leaks, as they repeatedly spawned harmful headlines for his political adversary. During a rally in Florida on July 27,2016, Trump even infamously called on “Russia” to “find the 30,000 emails” that he believed were missing from Clinton’s private email server.

Mueller is probing Trumps Russian dealings before the campaign

“I think you will probably be rewarded mightily by our press,” Trump told the campaign crowd.

Mueller’s investigators are also looking at how much Trump knew about the Russian hacks and whether his campaign in any way colluded with the Kremlin’s efforts.

After the 2016 election, the U.S. intelligence community released a unanimous report concluding that the Russian government directed the hacking efforts in a deliberate attempt to sow discord among American voters and, at least in part, help Trump win the election.

Despite that assessment, Trump has yet to unanimously assert that Russia meddled in the 2016 election on his behalf. He has also continued to blast the sweeping investigation into Russian meddling as a “hoax” and a politically-motivated “witch hunt” even though four of his associates have been charged in the probe, including his ex-national security adviser Michael Flynn.

A major question mark that remains is whether any Americans will be charged for participating or knowing of the Russian hacks. One source hinted that a new indictment could include unnamed American co-conspirators to pressure them into cooperating with Mueller’s probe.