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 from the sea," he said, adding: "The island is now without electricity."

The helicopter fell shortly after takeoff from Galata, the nearest coastal village on the mainland facing Poros, 170 kilometres southwest of Athens.

The coastguard said search crews, including six of its vessels, divers and a rescue helicopter, were examining the wreckage site.

Poros is a small picturesque island off the eastern coast of the Peloponnese that is popular with holidaymakers.