ANTANANARIVO (AFP) - A Madagascan minister swam some 12 hours to shore on Tuesday (Dec 21) and survived, after the helicopter he was in crashed off the island's north-eastern coast, authorities said.

The cause of Monday's crash was not immediately clear, police and port authorities said.

Mr Serge Gelle, the country's secretary of state for police, and a fellow policeman reached land in the seaside town of Mahambo separately on Tuesday morning, apparently after ejecting themselves from the aircraft, port authority chief Jean-Edmond Randrianantenaina said.

In a video shared on social media, Mr Gelle, 57, appears to be lying exhausted on a deck chair, still in his camouflage uniform.

"My time to die hasn't come yet," said the general, adding that he was cold but not injured.

The helicopter was flying him and some others to inspect the site of a shipwreck off the north-eastern coast on Monday morning. A wooden vessel, believed to be a cargo ship carrying passengers illegally, had sunk in the Indian Ocean with 130 people on board.

At least 64 people died in that disaster, gendarmerie general Zafisambatra Ravoavy told AFP on Wednesday. Five children were among the dead.

Mr Ravoavy earlier said that Mr Gelle had used one of the helicopter's seats as a flotation device.

"He has always had great stamina in sport and he's kept up this rhythm as minister, just like a thirty-year-old," he said. "He has nerves of steel."

Mr Gelle became a minister as part of a Cabinet reshuffle in August after serving in the police for three decades.