The late North Korean leader, Kim Jong-il, died from a heart-attack brought on by a temper tantrum over sloppy work on a crucial power station, reports in a South Korean newspaper claim.

According to unnamed sources quoted in Chosun Ilbo, a conservative national newspaper, Kim Jong-il died in a fit of rage after being briefed about a leak at a hydro-electric power station.

The reports claim that Kim became violently angry after hearing that there was a leak of water at the power station in Huichon, which is about 120 kilometres (75 miles) north of the capital.

The newspaper quotes a source, who asked to remain anonymous, saying: "After being briefed about the leak, Kim Jong-il lambasted officials and ordered them to repair it

"He rushed to make an on-site inspection of the facility unable to contain his anger and died suddenly."

The source also told the paper that the problems with the Huichon plant were critical: “It wasn’t just a crack. The safety of the entire dam was in question,” they are quoted as saying.

The power station, which is located in Huichon, Jagang Province, was built to supply a significant proportion of Pyongyang's electricity and to ease the power shortage in the capital.

The project was considered key for Kim Jong-il with him paying making at least eight visits to the site since work started in 2009.

Hydro-power is so important in energy starved North Korea that the nation’s coat of arms even features a hydro plant.