Volunteers said eight people were rescued from the boat, which was headed for Malaysia, a coveted destination for thousands of Rohingya Muslims fleeing persecution and poverty in Myanmar and Bangladesh.
It was unclear from where the boat had set off.
“We found dead bodies starting from August 7,” said Min Htal Wah, chairperson of Shwe Yaung Metta Foundation, a rescue organisation based in the coastal Rakhine region of Myanmar.
“Within three days, we found 17 dead bodies…We found some people alive,” he said, adding 10 women were among the dead.
A Rohingya aid worker in Maungdaw township on the border with Bangladesh said the boat had departed in bad weather and that about 500 others were still hoping to cross to Malaysia.
Nearly 1 million Rohingya live in crowded conditions in Bangladesh, among them those who fled a deadly crackdown in 2017 by Myanmar’s military, which denies committing crimes against humanity.
An untold number of them have died at sea from disease, hunger and fatigue as they attempt to reach Muslim-majority Malaysia and Indonesia in rickety boats.