A fire tore through a warehouse of Cheil Industries Inc., a key affiliate of Samsung Group, killing one warehouse security officer, police said Monday.

The fire started at the seventh floor of the seven-story clothing warehouse at 2:16 a.m. in Gimpo, a rural city west of Seoul. Firefighters were still struggling to extinguish the fire as of 1:30 p.m.

Police suspect an arsonist is behind the fire.

A man in his 50s was seen in footage from security cameras at the warehouse moving a plastic box into an elevator about one hour before the fire was reported, said Chung Seung-youn, a police official handling the case.

"Butane gas cans were found at the fire scene," Chung said, indicating that the fire may have been set deliberately.

Chung said investigations are under way to try to identify the person.

Officials of Cheil Industries, Samsung's clothing arm and virtual holding company, were not immediately available for comment on Monday, a public holiday for Buddha's birthday.

Samsung Group is South Korea's largest family-controlled conglomerate. (Yonhap)