South Korea has said a government official killed by North Korean sailors wanted to defect, concluding that the man, who had gambling debts, had conveyed his intention of resettling in the North.

North Korea accused South Korea of sending ships across the disputed sea boundary to find the body of a man recently killed by North Korean troops, warning the alleged intrusion could escalate tensions.

North Korean leader Kim Jong Un has apologised over the killing of a South Korea official near the rivals’ disputed sea boundary, saying he is “very sorry” about the “unexpected” and “unfortunate” incident, South Korean officials said.

North Korean troops shot a South Korean government official who may have attempted to defect and set his body on fire, after they found him on a floating object in water near their disputed sea boundary, according to Seoul.