By Kang Hyun-kyungIn the wake of the announcement of the death of North Korean leader Kim Jong-il, speculation has mushroomed over the cause, mainly because of the extreme secrecy in the Stalinist state.North Korea’s Central News Agency reported Monday that Kim died of a heart attack last Saturday on a train while heading to an unidentified destination.Previously, the late North Korean leader had suffered two strokes; and his declining health had spurred speculation among those outside the North that his death was near.Given this, the announcement wasn’t unexpected.However, there are some North Korean defectors here who remain suspicious of the state-controlled media’s report on the cause of his death, raising very cautiously the possibility of Kim having been murdered.An Chan-il, a political scientist, didn’t rule out the possibility that the North Korean leader might have been killed by those harboring discontent with the way he ruled the country.“After his third son Jung-un was named for a dynastic leadership succession, many military officers, especially those in their 50s, were dismissed. I think these people could have held deep resentment about Kim and North Korea’s next leader,” he said.“A rumor is circulating that earlier a high-ranking North Korean official was shot dead. This has yet to be confirmed, but such talk is evidence that discontent was brewing among some people in the North.”An, 57, speculated the North Korean military’s dwindling power could have spurred brewing displeasure among some military officers, especially those eliminated from power.Under the Kim Jong-il regime, the political scientist said, they had complained about their status as the military-first policy showed signs of retreating.“As their vested interests were hurt due to Kim Jong-il, I would not rule out the possibility that some military officers, who believed their clout and influence had been damaged, could have played a role in his death,” An said.Rep Chun Yo-ok of the ruling Grand National Party (GNP) also raised the possibility that Kim might have been killed as a result of a power struggle inside the North.Another North Korean defector, however, remained cautious about this.Kim Seong-min, the representative of Free North Korea Radio based in Seoul, said he believed the North’s announcement on Kim’s death as there was no evidence backing foul play.North Korea said that the cause of Kim’s death was confirmed after the authorities there carried out an autopsy Sunday, the day after he died.