"We are yet to find out why he had gone there," an ATS officer said on condition of anonymity.
NIA and other agencies have arrested about 20 suspected terrorists this month all over India.
Other terror suspects too had visited Panvel subsequently, the officer said, without revealing any names.
Last week, the state ATS, in a joint operation with the National Investigation Agency, arrested three men: one from Mazgaon area of Mumbai, another from Mumbra area in Thane and the third from Aurangabad.