|Indon Mohd Safyan (above right) is examined by a doctor|
The seven -- kidnapped June 23 -- were due to be executed Aug. 15 after a ransom deadline of $5.4 million passed.
Maj. Filemon Tan Jr., spokesman for the army's Western Mindanao Command, confirmed Mohammad Safyan escaped from the hands of the Abu Sayyaf on Wednesday.
Citing an official report from the Sulu Provincial Police Office, Tan said Safyan, 28, was found stuck in fishing nets by locals on the shore of a town in southern Sulu province at around 7.30 a.m. (2330GMT Tuesday).
"Sayfan was seen by the residents floating and was trapped in fishnets at the place of rescue," Tan said. "He was immediately brought by the residents to the Municipal Police Station of Luuk, Sulu."
According to Tan, reports from ground units disclosed that Safyan escaped from a mangrove farm when his captors declared that they would behead him.
Tan said Safyan -- abducted from a tugboat in the Sulu Sea near the Philippines border June 23 along with six other crew -- will be brought to the Sulu Provincial Police Office for processing and documentation prior to being sent back to his family.
He added that troops had been directed to the area to try and locate the remaining kidnap victims and rescue them.
Since 1991, the Abu Sayyaf -- armed with mostly improvised explosive devices, mortars and automatic rifles -- has carried out bombings, kidnappings, assassinations and extortions in a self-determined fight for an independent province in the Philippines.
It is notorious for beheading victims after ransoms have failed to be paid for their release.
Safyan's escape lowers the number of Indonesian hostages in Abu Sayyaf hands to six, although it is also holding a Norwegian, a Dutchman, three Malaysians, and seven Filipinos.
On Tuesday, suspected Abu Sayyaf militants also abducted a public school teacher in Patikul town in Sulu province.
The Abu Sayyaf is among two militant groups in the south who have pledged allegiance to ISIL, prompting fears during the stalling of a peace process between the government and the country's biggest Moro group, the Moro Islamic Liberation Front, that ISIL could make inroads in a region torn by decades of armed conflict.