The Piraeus prosecutor has filed felony arson charges against the captain and 12 crew members of the yacht Persefoni I, from which fireworks allegedly sparked a forest fire on Friday on the island of Hydra.
The 13 defendants have been granted a continuance to testify before the magistrate next Wednesday.
The accused were arrested on Saturday as part of an investigation into the fire's cause.
Authorities are in the process of temporarily confiscating the Persefoni I, which was chartered by 17 individuals from Kazakhstan.
Police have gathered information from vessels in the area during the incident.
A captain from a nearby vessel reported seeing fireworks from a boat in the area, and his testimony is expected to be crucial.
