Seven bodies were found Sunday in the seas of Sitangkai, Tawi-Tawi.
The bodies of six females and one male, recovered by local fishermen in different areas along the Sitangkai reefs, are believed to be passengers of a boat that sunk late last month.
The Philippine Coast Guard earlier said 16 passengers were declared missing, including the operator of the boat.
Search and retrieval operations for 8 more passengers are ongoing.
According to a survivor, they departed Banarani Island in Sapa-Sapa, Tawi-Tawi on July 29 en route to Sabah, Malaysia when they encountered rough sea conditions.
Authorities said the passengers are possible victims of human trafficking on their way to Malaysia passing through the southern backdoor.
The Philippine Coast Guard also revealed that the vessel had no permission to travel and to carry passengers.
Authorities said they are trying to identify the bodies.