Speculation has mushroomed over the cause of North Korean dictator Kim Jong Il’s death, mainly because of the extreme secrecy in the Stalinist state, according to The Korea Times.

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.

But some some North Korean defectors tell the Times that they 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.”

READ MORE: NEWSMAX