The Bali Water Police said on Wednesday that they had successfully foiled an attempt to smuggle 37 green turtles to the island.
The police also said they had arrested four suspects in the case.
Bali Police chief Ronny Franky Sompie said they found the turtles on a traditional boat near Padanggalak beach in Denpasar, Bali. It was suspected that the boat intended to transport the turtles to Serangan Island, also in Bali.
"The boat carrying 37 green turtles was found when our Water Police team conducted a patrol last night [Wednesday]. Four crew members from the boat are being interrogated," Ronny told journalists after releasing the turtles at Sanur beach on Thursday.
During the interrogation, the four suspects reportedly confessed that they had brought the turtles from Madura, East Java.
"We are still deepening the investigation," Ronny said.
Turtle trading is a criminal offence in Indonesia. Violators can face a maximum of five years in prison and a fine of up to Rp 100 million (S$10,135), according to the 1990 Conservation of Biodiversity and Ecosystems Law.