One person is confirmed dead and about a dozen are still missing two days after an overloaded ferry capsized in rough rapids on a remote Borneo river, Malaysian police said Thursday.

The accident happened Tuesday on the Rajang river, Malaysia's longest, deep in the interior of the vast island of Borneo amid a spike in travel for a festival this weekend celebrated by indigenous tribes.

"This morning a corpse was found not far from the accident location. He was a 44-year-old male," said Bakar Anak Sebau, police chief of the town of Belaga.

More than 190 people have been reported to have survived the capsizing of the express river ferry, which was massively overloaded. Authorities have said its capacity was around 70.

The distant location of the accident in the interior of the Malaysian state of Sarawak has hampered rescue efforts and the flow of solid information.

Bakar said about 12 people were still believed missing but the exact number remained unclear due to the lack of a passenger manifesto for the vessel.

"As of now, we just can't give a clear number," he said.

The boat was heading downstream from Belaga, full of travellers on the move for the coming weekend's Gawai festival, an annual cultural and religious observance for Borneo tribes.

Authorities want to search the submerged boat for victims or survivors, but have said rescue teams have been thwarted by strong currents and no visibility in the Rajang's fast-moving waters, which are brown with sediment.

Bakar said teams would try to tow the boat to a safer location. An earlier effort to do so failed.

Sarawak is Malaysia's largest state by area but also one of its least developed. It is one of two Malaysian states on Borneo, which is also shared with Indonesia and the sultanate of Brunei.

Many members of the indigenous tribal groups who predominate in Sarawak still live in traditional wooden longhouses in the interior, where fast-flowing but treacherous rivers are the quickest mode of travel.