Police said Tuesday that they have failed to determine the cause of ferry owner Yoo Byung-eon's death.
Yoo, a fraudulent businessman and leader of a crackpot cult, was widely blamed for the April 16 ferry disaster and became the target of a nationwide manhunt that went on long after his decomposed body was discovered on a remote hillside on June 12.
A special investigative team formed last month to investigate Yoo was dismantled on Tuesday.
Police in Suncheon, South Jeolla Province, where the corpse was found, analyzed footage from 22 CCTV cameras in the area as well as the black boxes of 11 vehicles but were unable to find any images tracing his movements in the region.
A police spokesman said, "We were informed by the National Forensic Service and scientific investigators that footage that may show Yoo was too hazy to confirm an exact match."
Yoo hid in a secret compartment in his hideout in Suncheon during a raid on May 25, and police believe he escaped on his own after investigators left. He is believed to have died alone while on the run between May 25 and June 2.
Police have put the date of his death at June 2 based on analysis of insects that fed on his decaying body. As no evidence of assault were found on his body, police believe he probably died of hypothermia.