The 6.12-meter reptile, nicknamed "Lolong", died at its pen in Bunawan town, in Mindanao`s Agusan del Sur province shortly after 8 p.m. on Sunday, Edwin Elorde, the town mayor said.
"(Lolong`s death) was very unfortunate," Santiago Cane, vice governor for Agusan del Sur province told Xinhua in a text message on Monday.
Elorde said in a phone interview that the reptile showed unusual sluggish activity hours before its demise, prompting local authorities to shut down an inland lagoon-turned resort at the upland village of Consuelo where Lolong was kept, from public.
The local government has been cashing in on the reptile as a tourism attraction in this sleepy town of more than 20,000 since the beast was captured in 2011.
"He has stopped eating his usual diet since last month. Actually, we`ve noticed unusual changes in the animal`s behavior right after last December`s typhoon," Elorde said, referring to last year`s storm that killed more than a thousand people in the region. "His belly had ballooned."
Lolong was captured in 2011 in the Agusan Marsh. Guinness World Records declared it last year as the world`s largest saltwater crocodile in captivity in the world.