Seoul (CNN) Do you enjoy playing violent video games? Then you can't avoid military service.

That appears to be the message South Korea is sending conscientious objectors. Prosecutors said they were investigating whether a number of men seeking exemption from military service played "online shooting games" in the past.

"We need to verify their genuine faith. So we need to examine their personal life," an official with the prosecutors office on the southern island of Jeju told CNN. "We check whether they had been attending (religious) service. Checking their history with shooting games is another method."

Around a dozen men are currently facing hearings to determine whether they can claim conscientious objector status in the wake of a landmark Supreme Court ruling in November ending South Korea's position as the world's leading jailer of those who refuse to join the armed forces.

"Refusing to enter the military due to a religious faith which forbids bearing arms is considered a justified reason to refuse duty," the court said in its ruling. "Therefore it cannot be criminally punished."

Oh Seung-hun (C), a Jehovah's Witness, speaks to the media after a court's verdict to overturn his conviction on refusing to do mandatory military service, at the supreme court in Seoul on November 1, 2018.

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