Navy officials say they believe they've recovered the remains of the sailor who disappeared from HMCS Montreal earlier this year.

A fisherman discovered human remains, including a Canadian navy uniform, Tuesday evening in the Baltic Sea off the coast of Poland, the navy said Thursday.

Leading Seaman Robert Leblanc was last seen Feb. 9. He was presumed to have fallen overboard and drowned while the ship was patrolling the Baltic Sea. A massive search was conducted, but Leblanc's body was not found.

The navy says it's likely the remains are those of Leblanc. But the mystery remains unsolved.

"No conclusions have been reached. It's an ongoing investigation," said Capt. Mark Giles, a navy spokesperson. "We'll look at all possibilities and we hope at some point we can come to some conclusion."

Two investigators with the military's National Investigation Service (NIS) are on their way to Gdansk, Poland, to retrieve the remains. An autopsy will be done by the Office of the Chief Medical Examiner of Ontario.

The NIS is an independent military police unit that investigates serious and sensitive matters involving defence property, Defence Department employees and military personnel.