Four men were trapping crabs in the waters off Kampung Tinagian, Tanjung Labian, on Wednesday when the crocodile lunged at the plantation worker in a pre-dawn attack.
The man's body with bite marks and scratches was recovered nearly 5km away at the beach near the army post at Kampung Tanjung Batu.
“The three friends could only watch as the attack happened in a split second,” Lahad Datu district police chief Rohan Shah Ahmad said, according to The Star.
"The friend vanished in an instant [into the water] before they could do anything," he said in a statement.
The body was found at 7.20am (local time) with bite marks on the left arm and head as well as scratches on the chest, back of the neck, and back, the police chief added.
The remains were brought to the Lahad Datu Hospital for an autopsy.
"This was the first such attack in Lahad Datu this year," the police chief said, advising the community to be "extra cautious" around sea and rivers.
Earlier in June, the remains of a missing 60-year-old were recovered from the stomach of a crocodile that was fatally shot by wildlife rangers in Sabah.
The remains of Addi Bangsa, who went missing at a river in Kampung Sungai Mas Mas, were found in the 4.29-metre-long and 800kg male crocodile, a Sabah Fire and Rescue Services Department spokesperson said.
A one-year-old body was mauled to death by a crocodile and the father was left severely injured while they were fishing off the coast of Lahad Datu in December last year.
The child was snatched from the canoe by the reptile, Daily Mail reported. The father tried to save the toddler but the reptile overpowered him, causing serious injuries.
The crocodile later emerged on the surface with the mutilated body of the child in its jaws before disappearing into the water with the corpse.