ZAMBOANGA CITY, Philippines -- Agents of the US Federal Bureau of Investigation (FBI) and local police have begun taking samples from a cadaver suspected to be that of wanted Indonesian bomb expert Ammar Usman or Dulmatin, Rear Admiral Emilio Marayag, commander of the naval forces in Western Mindanao said Tuesday.

The FBI will subject the samples to a DNA test to confirm if the remains dug up by Marines Monday in Barangay (village) Balimbing, Panglima Sugala, Tawi-Tawi province, are indeed those of the Jemaah Islamiyah (JI) operative.

Marayag said the cadaver is most likely one of several men who clashed with government troops late last month.

He said the samples from the cadaver would be compared with those taken from Dulmatin’s children, who were recovered in the southern Philippines last May.

Dulmatin and fellow JI operative Umar Patek are the main suspects in the 2002 Bali bombings that killed more than 200 people in 2002. Both have been hiding in the Philippines since 2003 and were said to be working with members of the Al-Qaeda-linked Abu Sayyaf.

An informant led troops from Marine Battalion Landing Team 2 and the Force Reconnaissance Battalion to the grave site at 4:30 p.m. Monday, said Navy spokesman Lieutenant Colonel Ariel Caculitan.

"A body was recovered and there is a strong possibility that it is Dulmatin's," Caculitan said in a phone interview. "It will have to go through procedures, including DNA testing, before we can confirm that it is Dulmatin's."

"Based on the description of the informant, [Dulmatin] suffered gunshots in the head, chest, and right foot. Based on our initial findings, the statement of the witness matched [with the exhumed remains]," said Marine Commandant Major General Ben Dolorfino.

Caculitan noted that Dulmatin was sighted in an encounter between Marines Abu Sayyaf fighters in Panglima Sugala town on January 31.

"If it is indeed Dulmatin, this will be a major breakthrough in the fight against terrorism," Caculitan said.

"This is a big blow to them, [Dulmatin] is the most priced personality in the ASG [Abu Sayyaf] and JI. He carries a $10-million reward," Dolorfino said.

Dolorfino said the informant was qualified to receive the $10-million bounty. He refused further questions on the informant's identity for security reasons.

The remains were transferred Monday night to Bongao town, also in Tawi-Tawi, to be prepared for transfer to Zamboanga, Dolorfino said.

Major Eugene Batara, spokesman of military forces in the south, said the DNA tests would likely take about a week. Once enough samples are taken, the body will be given a "decent burial" in Zamboanga, he said.

Dulmatin is an Indonesian national from a wealthy family who is believed to be one of JI's top bomb makers.

In December 2006, Marines recovered remains believed to be those of Abu Sayyaf chieftain Khadaffy Janjalani in Patikul town, Sulu province, over three months after he was reported wounded in an encounter there.

A DNA test by the Federal Bureau of Investigation the following month confirmed the remains as Janjalani's.

The Abu Sayyaf -- the smallest and most radical of the Islamic separatist groups in the southern Philippines -- is believed to be providing protection for JI members in return for bomb-making expertise and training.

US troops and military advisers have been in the southern Philippines for more than a year providing training and intelligence for the Philippine military hunting JI extremists and their local partners the Abu Sayyaf.

In another development, Philippine troops arrested an Indonesian man and his local Muslim hosts during a raid on a remote southern area being monitored for possible Islamic militant activity, officials said.

The Indonesian, known to his neighbors as Salman, was detained Sunday in an army raid on the home of a local Muslim man in the village of Piso on Mindanao Island, said Dequincio Pante, police chief of Banaybanay town.

A senior military source described the arrest of the Indonesian as a "major" achievement, but could not provide details about the case without top-level authorization.

It was not clear if this incident was linked to the Jemaah Islamiyah.