"Russia, if you're listening, I hope you're able to find the 30,000 emails that are missing."

This statement by Donald Trump is one of the most memorable of the 2016 presidential election campaign. Most voters saw it simply as the Republican nominee needling Hillary Clinton, his Democratic opponent, after WikiLeaks began posting hacked emails from the Democratic National Committee.

Malcolm Nance, an author, security consultant and former U.S. Navy intelligence officer, has a different view of it.

"When Trump made that statement on July 27," Nance says, "he knew Russian intelligence was working for him, in his favor."

Nance's comments are part of a stunning Dutch documentary, "The Dubious Friends of Donald Trump," about the U.S. president's alleged ties with Russian mobsters and other unsavory characters. The first episode of the doc, which states that Trump in the early 2000s became "dependent on shady cash flows," seeks to provide context for the allegations that the Trump campaign colluded with Russian hackers and spies who sought to get the Republican candidate elected.

President Trump, the documentary claims, is deeply involved with Russian "syndicate crime boss" and former FBI informant Felix Sater. (Trump has stated he would have a hard time recognizing Sater if the man walked into the room.) The film also delves into Trump's longstanding business relationship with Kazakhstan-born Bayrock LLC chief Tevfik Arif, who Trump biographer Michael D'Antonio says "probably" has funneled illicit money into the U.S.

Bayrock, says the Pulitzer Prize-winning D'Antonio, is "led by people with extremely shadowy backgrounds and profiles."

Why would Trump, a famous and wealthy businessman for more than 30 years, get involved with such characters?

To answer that question, the documentary's producers turned to James Henry, a lawyer, tax-evasion expert and "economic investigator."

Henry says that because of Trump's 1990s bankruptcies, which were mostly related to his involvement in the casino business, "none of the major New York banks would lend to him. Trump was pretty much unfinance-able."

He continues:

"The only way he was able to finance his resurrection after 2000 was the torrent of money flowing out of Russia and former Soviet Union countries like Kazakhstan, Azerbaijan. The investors he got, at that point, were looking for safe havens or opportunities to launder money -- proceeds from, basically, criminal enterprises."

Adds D'Antonio:

"It's likely there is Russian money that has flowed into Trump Organization entities in one way or another, and that some of this money may have sources that are scandalous and would pose a big problem for a president. And if the Russians have that information it could be what they're holding over him."

It's hard to say whether such accusations could end up being a real legal problem for the president, seeing as the Trump experts interviewed in the documentary carefully use qualifiers like "probably" and "likely." Certainly none of the accusations at this point has been proven in court.

But this much is made clear by watching "The Dubious Friends of Donald Trump": The FBI and Congressional investigations into Russian meddling in the U.S. election aren't Trump's only potential legal problem. New York State Attorney General Eric Schneiderman is reportedly pursuing a fraud case and other investigations targeting the president's business empire.

"The Dubious Friends of Donald Trump" includes an interview with lawyer Frederick Oberlander, who has led a civil tax fraud case against Trump. Oberlander had this to say:

"I have concluded, without any question, that Donald Trump may be credibly charged with participating in a racketeering conspiracy based on what happened with Bayrock."

Below you can watch an English-language version of the documentary's first episode:

-- Douglas Perry