Police are carrying out a search of the home of the Derry man suspected of having joined rebels in Syria.
Earlier this year, it was reported 25-year-old Eamon Bradley, from Melmore Gardens in Creggan, joined rebels battling the regime of President Assad.
The former pupil of St Joseph’s Boys School is understood to have told his mother he was going to Turkey on holiday but instead went to Syria.
Today’s search follows the arrest of a 25-year-old man in the Creggan.
A PSNI spokesperson said the man was arrested by detectives from Serious Crime Branch as part of inquiries into reports of alleged activity in Syria.
The spokesperson added: “The suspect was arrested in the Creggan area of the city and has been taken to Antrim police station for questioning.”