Holy See spokesman Fr Federico Lombardi said one of the men was Polish born Mgr Bronislaw Morawiec.
He's an administrator at St Mary Major Basilica, a Rome church where Pope Francis often goes to pray.
The other, Josef Wesolowski, is also from Poland and was defrocked last year after being found guilty of child sex abuse by a Vatican court.
Mgr Morawiec has already been convicted of fraud by the Vatican, Fr Lombardi said.
No other details of the investigation have been released.