The drone was discovered on Monday and has now been examined, according to military prosecutor Bartosz Okoniewski.
It contained a warhead with a detonator, he says, without revealing the drone's equipment or possible targets.
Defence Minister Wladyslaw Kosiniak-Kamysz confirmed that the Gerbera-2 drone was found in the sea off the village of Rusinowo in northwestern Poland. The Szczecin prosecutor's office is launching an investigation into the incident, it was announced on Wednesday.
Poland borders Ukraine and the Russian exclave of Kaliningrad. Polish airspace and territory have been repeatedly violated by drone flights since Russia launched a full-scale invasion of Ukraine in 2022.
