A South Korean man initially thought to have been killed by an exploding mobile phone battery was in fact crushed by a quarry vehicle, police have said.
The man was found dead on Wednesday with a melted battery in his pocket and his heart and lungs punctured.
But police in Cheongju said a colleague later confessed that he had backed into the victim while reversing a construction vehicle.
They said the colleague had tried to cover up the accident.
Police are investigating whether the battery exploded during the accident or the colleague set it on fire.
The body of the 33-year-old South Korean was found in a quarry where he worked in Cheongwon County in North Chungcheong Province, 135km (85 miles) south of Seoul.
A doctor had said burns on the man's chest, and fractures of his ribs and spine as well as haemorrhaging in the lungs could have been caused by an exploded battery.
But preliminary autopsy results later suggested damage to the man's organs was too heavy to have been caused by such an explosion, prompting police to investigate the colleague who reported the death.
Police said the phone had been made by LG Electronics.
The company said on Friday that it had confirmed the death had no connection to its handset or battery, in contrast to previous media coverage.
"LG rigorously tests all the products not only for functionality and design, but safety as well," the company added.