( CNN ) Philippines security forces killed one of the FBI 's most wanted terrorists during an otherwise disastrous mission in the south of the country last month , DNA tests indicate . Commandos in pursuit of the notorious Malaysian bomb maker Zulkifli bin Hir , also known as Marwan , took a DNA sample from the scene of their assault on their target , and passed it to the FBI for testing . Marwan -- believed by the FBI to a member of southeast Asian terror group Jemaah Islamiyah 's central command -- had previously been falsely reported dead after a raid by Philippine security forces in 2012 . But preliminary results from the tests showed a link with a known relative of Marwan , said David Bowdich , assistant director in charge of the FBI 's Los Angeles field office . While the testing could not yet provide `` absolute identification , '' he said , `` the results do support that the biological sample provided by Philippine authorities came from Marwan . '' Marwan 's brother , Rahmat bin Hir , is in a California prison following a 2007 arrest for conspiracy to provide `` material support to terrorists . '' The FBI has been offering a $ 5 million reward for information leading to Marwan 's capture , in the wake of his 2007 indictment on terror charges in a California court . It accuses him of being a supplier of IEDs to terrorist organizations , and having conducted bomb-making training for terror groups , including the Philippines-based Abu Sayyaf . `` He was the leader of Jemaah Islamiyah within the Philippines , the most senior figure , '' said Clarke Jones , a terrorism expert at Australian National University , who works on de-radicalizing Islamist terrorists in Philippine prisons . The Philippines has been fighting an insurgency in the predominantly Muslim south for years , and last year signed a peace agreement with the Moro Islamic Liberation Front ( MILF ) , the largest rebel group in the region . Marwan , was believed to be affiliated with the Bangsamoro Islamic Freedom Fighters ( BIFF ) , a hardline splinter group which rejected the peace deal , and had claimed responsibility for bombings in the region , said Jones . At large since 2003 , he had been able to operate in relative safety from his base in the southern Philippines , said Jones . He said the killing of Marwan would `` without a doubt '' disrupt the BIFF 's activities . `` He was a key agitator in disrupting the peace accord between MILF and the Philippines government , '' he said . `` This is a major blow to the militants down south . '' The mission to get Marwan late last month went disastrously awry , with 44 members of the police 's elite Special Action Force ( SAF ) unit killed in a 12-hour firefight after ambushing the bomb maker in the southern province of Maguindanao . Authorities said that as commandos were retreating from their assault , they came under fire from members of the BIFF . In maneuvering away from the BIFF onslaught , they strayed into territory controlled by the MILF , and further fighting ensued , shattering a three-year ceasefire . A national day of mourning was declared as the men were laid to rest . In a eulogy , the deputy director of the Special Action Force , Police Chief Superintendent Noli G. Talino , expressed his guilt at having failed to safely extract the fallen men . `` Is it worth it ? One international terrorist equivalent to 44 SAF troopers ? '' he asked . `` I 'm sure if you will ask them , it is worth it . '' READ MORE : Dozens of Philippine police killed in raid on 'high value ' bomb makers . READ MORE : Philippines honors 44 slain commandos with day of mourning . CNN 's Arlene Samson-Espiritu contributed to this report .
The FBI says a DNA sample taken from a raid in the Philippines matches a relative of Marwan . A U.S. official told CNN that Marwan’s family has been informed and is cooperating with authorities. 44 elite Philippine commandos were killed in the raid on his hideout last month .