LESBOS, Greece — A Norwegian photographer arrested on espionage-related charges on the Greek island of Lesbos has been released from custody after appearing Monday at a public prosecutor’s office.

Court officials said the 75-year-old Knut Bry had been released after giving evidence for more than three hours but the investigation into his alleged activities remains ongoing. Bry was detained last week for photographing Greek coast guard and navy vessels at the island’s main harbor without permission. Photography and memory storage equipment were seized in a police search of his hotel room.

The charge of illegally obtaining state secrets brought against Bry is punishable by imprisonment of at least one year.

Bry’s arrested triggered small protests on Lesbos and in Norway, while supporters online posted photographs of Greek coast guard vessels that are in plain view at the island’s main harbor, Mytilene. Bry, who denies any wrongdoing, works with a local nonprofit organization, Lesvos Solidarity, that helps migrants and refugees. Lesbos busiest point of entry into the European Union during the 2015-16 refugee crisis, when hundreds of thousands of people fled wars in Iraq and Syria.

“We are very happy with outcome. Everyone at our organizations is very happy,” Nikos Markou, a spokesman for the charity group told the AP moment’s after Bry’s release.