The bodies of three men were recovered near the Greek island of Poros on Tuesday after a private helicopter crashed through power cables and into the sea, state agency ANA said.
Coastguard spokesman Nikos Lagadianos said a total of three people were believed to have been on board -- a Greek pilot and two foreign passengers.
ANA said the two foreigners were Russian.
A local official had earlier said the crash knocked out power across the small island.
"There was a great flash and the helicopter's fuel exploded," deputy Poros mayor Yiorgos Koutouzis told state TV ERT.
"It hit power cables around a 100 metres (yards) from the sea," he said, adding: "The island is now without electricity."