The Treasury Department wants to know if some of Michael Cohen's financial information was leaked.
The department's inspector general launched an investigation after Stormy Daniels' attorney Michael Avenatti released documents that he says tie the Trump attorney to a Russian oligarch.
Avenatti claims the oligarch paid Cohen about $500,000 through Essential Consultants, Cohen's shell company.
Here's where the Treasury Department comes in: Financial institutions always look out for suspicious transactions, and when something pops up, they submit a suspicious activity report with the Treasury's Financial Crimes Enforcement Network.
Avenatti hasn't said where he got his information. But the allegations in the documents could be based on a suspicious activity report, and that's what the Treasury Department watchdog is now investigating.
Additional reporting from Newsy affiliate CNN.