Sub Lieutenant Abbigail Cowbrough was on board a Cyclone Sikorsky CH-148 helicopter that, according to NATO, crashed after taking off from the Canadian frigate Fredericton on Wednesday, her father Shane Cowbrough said on social media.

The information was not immediately confirmed by the Canadian ministry of defense. It has, however, reached out to the families of all who were aboard the helicopter, it said.

"I am broken and gutted," said her father in the Facebook post. "Today I lost my oldest daughter Abbigail Cowbrough in the crash involving the Cyclone from HMCS Fredericton. There are no words.

"You made me forever proud. I will love you always, and miss you in every moment. You are the bright light in my life taken far too soon."

A Greek military officer told AFP debris from the helicopter wreckage has been found in the Ionian Sea.

Six crew were aboard the helicopter when it disappeared, the officer said on condition of anonymity.

Greek public television also reported that a body has been found amid the wreckage in international waters off the Greek island of Kefalonia.

The Canadian Armed Forces have said it lost contact with the helicopter deployed on board HMCS Fredericton, which was participating in NATO exercises off the coast of Greece.

"Search and rescue efforts are currently under way," it added.

Italian, Greek and Turkish frigates were taking part in the exercises along with the Canadians.