KUALA LUMPUR (AFP) - The boat that sank off Malaysia with 97 Indonesian illegal migrants was likely carrying three times more passengers than it could safely transport, authorities said on Thursday as they expanded a search for 26 still missing.

Nine bodies have been found after the vessel, overloaded with people heading home to Indonesia for the Muslim fasting month of Ramadan, sank early on Wednesday not far from shore off western Malaysia.

Sixty-two people have been rescued and officials believe some of the 26 still missing made it to land and fled the area to avoid being apprehended by police.

Authorities said the boat was believed to measure no more than 9m long and 2m wide.

"The boat was too small to ferry 97 people. The boat must have been very cramped," said Mr Mohamad Zuhri, spokesman for the Malaysian Maritime Enforcement Agency (MMEA).

Mr Mohamad said the capacity of a boat of such dimensions was about 30 passengers.

On Wednesday, divers were deployed, more vessels brought in and the search zone expanded along the coast in hope of finding more survivors, said Mr Mohamad Hambali Yaakup, coordinator of the response for the MMEA.

"We have deployed divers and a total of 25 marine craft and a helicopter to sweep the coastal area for possible survivors," he told AFP.

The incident occurred at night near Port Klang, the country's main seaport.

Mr Hambali said the divers would try to determine what caused the boat to sink and to view any markings that would help identify the boat's owner and operator.

The survivors include 49 men, 12 women and one child, he said.

They have been detained by police and were not available to the media.

Large numbers of Indonesians annually return home from Malaysia for Ramadan, which this year begins around the end of June and will culminate in late July with Eid al-Fitr, Islam's biggest festival.

Both Malaysia and Indonesia are Muslim-majority.

Relatively affluent Malaysia is a magnet for migrant workers from poorer neighbours such as Indonesia, Bangladesh and Myanmar seeking low-paying plantation, construction, and factory work that is typically shunned by Malaysians.

Around two million illegal immigrants - the vast majority of them Indonesian - are estimated to be working in the country.

Accidents, however, are frequent as thousands annually risk the sea journey to and from Malaysia in rickety boats, often adding to the danger by travelling at night to avoid detection.