It was reported in the 2015 election. The Mueller investigation. And it's in the Epstein Files.
Here's how it worked. Trump would get a loan from Duetche Bank. Russians would pay cash for condos in Trump properties. He then would use that cash to buy a property. Which he would then sell to.... a Russian oligarch at ridiculous markups a year or two later.
Then pay the loan off.
It happened so frequently that JP Morgan reported it to the FBI and stopped doing business with Trump.