FLASHBACK: Trump abruptly walked out of interview after being asked about Felix Sater connections

Felix Sater, a Trump-linked Russian-born businessman who in 1998 pleaded guilty to taking part in a mafia-related stock fraud scheme, is at the center of the latest revelations surrounding the Trump campaign's potential collusion with Russian government officials to influence the 2016 presidential election.

The most recent revelations about Sater are newly unearthed emails that show Sater boasting to longtime Trump attorney Michael Cohen that he could get the Russian government's help to "engineer" a Trump election victory if the then-candidate agreed to a deal to build a new Trump Tower in Moscow.

"Our boy can become president of the USA and we can engineer it,” Mr. Sater wrote in one email to Cohen. "I will get all of Putin's team to buy in on this, I will manage this process."

Trump has worked with Sater for years, despite the fact that he took part in a $40 million mob-related stock scam. Back in 2013, British program BBC Panorama directly asked Trump why he was still doing real estate deals with Sater, and Trump frantically tried to deflect the question before walking out of the interview all together.

"Well, first of all, we were not in business together, that was a licensing deal," Trump said.

"But your name's on it, Mr. Trump!" replied reporter Jon Sweeney.

"Excuse me, but I don't know, you're telling me things that I don't even know about," Trump replied. "I mean, you're telling me about Felix Sater. I know who he is..."

Sweeney then interrupted him.

"But for a year, you stayed in bed with Felix Sater, and he was connected with the mafia!" Sweeney pressed.

"Again, Jon, maybe you're thick, but when you have a signed contract, you can't, in this country, just break it," Trump replied. "And by the way, Jon, I hate to do this, but I do have that big group of people waiting, so I have to go."

Trump at that point got up and walked out of the interview.

Sater’s financial relationship with Trump dates back to at least 2003, when the Trump Organization rented out office space to Sater’s former company.

Even though Trump initially tried to distance himself from Sater after news of his criminal past came to light in 2007, he subsequently tapped Sater in 2010 to scout out real estate. Additionally, Sater presented clients with business cards that claimed he was a senior adviser to Trump, and his office was on the same floor as Trump’s office in Trump Tower.

Watch the Trump BBC Panorama interview below.