The Vatican said its investigation into suspect transactions at the bank may extend beyond those of the cleric, Monsignor Nunzio Scarano, Italy's ANSA news agency reported.
Scarano is charged with conspiring with a former Italian spy and a financial broker to bring 20 million euros back to Italy from Switzerland.
The government claims a family close to Scarano acquired the money through tax evasion.
The Vatican suspended the prelate a month ago from his job as head of analytic accounts at the See's asset-management agency.
Italian authorities arrested him June 28.
The Vatican has said it will fully cooperate with the investigation.
Notable deaths of 2014 [PHOTOS]
N. Korea to bar foreign entry due to Ebola fear