SEOUL (AGENCE FRANCE-PRESSE) - A piece of human bone recovered from the site of South Korea's Sewol ferry wreck has been identified as one of the missing victims, officials said on Wednesday (May 17), the first such confirmed find since the vessel was raised in March.

The 6,800-tonne ship sank off the country's southwestern coast three years ago in one of the country's worst maritime disasters, claiming more than 300 lives, mostly high school students on an excursion.

The bodies of nine victims have never been found, and the 145-metre Sewol was raised intact at the relatives' insistence to prevent any trapped remains being lost.

"The result of a DNA test on a bone piece identified it as Danwon high school teacher Ko Chang Seok," the maritime ministry said in a statement.

Workers are sifting through silt and debris piled up inside the hull of the ship to search for human remains, while divers are scouring the sea bed where the ferry had been lying - where the bone was recovered two weeks ago.

The DNA test was completed earlier than expected because it was in "good condition", the statement added.

The ministry said the National Forensic Service was conducting DNA tests on suspected human bones recovered on four other occasions this month.

The Sewol sinking dealt a crushing blow to now-ousted president Park Geun Hye.

Investigations concluded the disaster was the result of numerous human factors, including an illegal redesign, an overloaded cargo bay and inexperienced crew.