The passenger, identified as Ali Yousefali Zamankhanpoor, holding passport issued by the Islamic Republic of Iran, was frisked on Friday after he passed through the green channel at the Chhatrapati Shivaji Terminus airport, the official added.
A passenger faces arrest or detention if he or she passed through the green channel with undeclared goods or currency.
Zamankhanpoor had landed at the airport on an Iran air flight from Iran.
"After checking his luggage, 90,000 US dollars worth Rs 47.52 lakh were found. Any passenger carrying beyond 5,000 US dollars will have to declare before the authorities. Zamankhanpoor has been subsequently arrested for not declaring the US dollars," the official added.