At one point, Khawaja hosted a Clinton campaign fundraiser at his home featuring Bill Clinton because Khawaja had contributed almost $1 million in contributions to the campaign. He hosted other political events, too, according to the indictment.

And, through his company, Khawaja donated $1 million to the Donald Trump inaugural committee, securing inauguration tickets for himself, Nader and another conspirator, the indictment said.

None of alleged conspirators have entered pleas in DC District Court, where they were charged.

The newly unsealed indictment adds to a collection of cases the Justice Department has brought cracking down on foreign political contributions and influence in the wake of the Robert Mueller special counsel investigation. In other pending criminal cases, prosecutors have alleged illegal contributions that went to many types of candidates and political interests, especially Republicans, and have sketched out efforts from several governments, especially Russia, to tap into American politics.

In the Mueller investigation, Nader had become a key cooperator and had given extensive information about his contact with a Russian and the Trump campaign. The special counsel's office investigators had asked questions about Nader's political networking, some of which touched on the new set of allegations, according to a source familiar with the investigation. Separately, Nader was charged with transporting child porn after he finished his cooperation with Mueller. He has pleaded not guilty and is in jail as that case progresses.

In all, the indictment amounts to 53 criminal charges.

Khawaja funneled some campaign contributions through the other alleged conspirators, according to the indictment.

(Khawaja and the others gave money to dozens, even hundreds, of political campaigns and groups from 2015 to 2016, for both parties, according to the FEC.)

Khawaja is also charged with giving bad information to a witness in the investigation, allegedly obstructing the federal grand jury in DC.

Foreign Country A, Candidate 1 and the candidate's spouse are unnamed in the indictment. But a source familiar with the case said the candidate was Clinton, and the indictment refers to related Nader WhatsApp messages about "the Big Lady." In another message, Khawaja describes the candidate as his "sister."

The country is in the Middle East, the indictment says.

Mueller's interest in Nader appeared to focus on his close relationships with the United Arab Emirates, a Russian businessman and people close to Trump -- and how he became a connector between a rich and powerful Russian, Kirill Dmitriev, and the Trump associates.

Nader was a key witness for Mueller as the special counsel pieced together a Seychelles meeting in early 2017 between Trump supporter Erik Prince and the prominent Russian government banker Dmitriev, who has close ties to Russian President Vladimir Putin. Nader's efforts to set up meetings with Trump surrogates are mentioned extensively in Mueller's report on Russian interference in the 2016 election, which resulted in no criminal charges against Americans for any interference conspiracy.

"Nader informed Prince that the Russians were looking to build a link with the incoming Trump administration," Mueller wrote about their interactions shortly after the 2016 election.