This week, New York developer Felix Sater is set to testify before Congress about his role in Donald Trump's attempt to build a tower in Moscow. A lawsuit filed Monday may provide new fodder for his inquisitors, with its claim that Sater, a longtime associate of Trump's, sought to use money stolen from a bank in Kazakhstan to help develop the building.

The suit by BTA Bank JSC alleges that Sater and the wealthy Kazakh businessman Ilyas Khrapunov explored financing the tower deal in 2012 with some of the $4 billion stolen a decade ago by Khrapunov's father-in-law, ex-BTA Chairman Mukhtar Ablyazov. While the Moscow plan fizzled, other transactions tied to Sater helped launder the purloined cash, the bank says.

"Sater helped Ablyazov, Khrapunov and others launder tens of millions of dollars in those stolen funds into the United States," according to the complaint filed Monday in Manhattan federal court. "Sater also tried to help them stash some of the stolen money overseas, including in real estate in Moscow."