Attorney Robert Baum said Friday he may use that information to appeal a magistrate judge's decision to deny bail for his client, 28-year-old Anna Chapman.
Chapman was the first of 10 spy suspects arrested over the weekend in the United States to be denied bail. She faces a charge of conspiring to act as an unregistered agent of a foreign government, which carries a potential penalty of five years in prison.
Prosecutors say an FBI agent posing as a Russian consulate employee asked Chapman to deliver a fake passport to another spy.
Baum says his client remains in solitary confinement in Brooklyn.