An industrial robot crushed a worker to death at a vegetable packaging plant in South Korea, police said Thursday, as they investigate whether the machine was unsafe or had potential defects.

According to police officials in the southern county of Goseong, the man died of head and chest injuries Tuesday after he was grabbed and pressed against a conveyor belt by the machine's robotic arms. Police did not release his name but said the man was an employee of a company that installs industrial robots and was sent to the plant to examine whether the machine was working properly.

The machine was one of two pick-and-place robots used at the facility that packages bell peppers and other vegetables exported to other Asian countries, police said. Such machines are common in South Korea's agricultural communities.

“It wasn't an advanced, artificial intelligence-powered robot, but a machine that simply picks up boxes and puts them on pallets,” said Kang Jin-gi, who heads the investigations department at Gosong Police Station. He said the police were working with related agencies to determine whether the machine had technical defects or safety issues.

Another police official, who did not want to be named because he wasn't authorised to talk to reporters, said police were also looking into the possibility of human error. The robot's sensors are designed to identify boxes, and security camera footage indicated the man had moved near the robot with a box in his hands, which likely triggered the machine's reaction, the official said.

“It's clearly not a case where a robot confused a human with a box – this wasn't a very sophisticated machine,” he said.

South Korea has had other safety accidents involving industrial robots in recent years. In March, a manufacturing robot crushed and seriously injured a worker who was examining the machine at an auto parts factory in Gunsan. Last year, a robot installed near a conveyor belt fatally crushed a worker at a milk factory in Pyeongtaek.