A South Korean court said on Wednesday it had reopened the case of the assassination of former president Park Chung-hee by his intelligence chief.

Park had ruled the country with an iron fist for more than 15 years when he was shot and killed by spy boss and trusted aide Kim Jae-gyu during a dinner in 1979.

Kim was subsequently sentenced to death by a military court for killing the head of state with the goal of "insurrection" and was hanged shortly after.

But his family appealed to the court to revisit the case in 2020, claiming that, while Kim had killed the president, he did it to put a stop to Park's ruthless dictatorship and not in pursuit of power.

They also say Kim was tortured during questioning and that he did not receive a fair trial.

"We have decided to reopen the case," a Seoul High Court official told AFP on Wednesday.

Lee Sang-hee, an attorney for Kim's relatives, said: "We will revisit the case by reviewing investigation records (from 1980)."

"We are not fighting on the issue of whether Kim killed Park. It is a fact, but over why... We will fight to remove the insurrection conviction," she told AFP.

Kim's sister Jung-sook said in a 2020 interview with AFP her brother's act wasn't out of self-interest.

"He was executed without telling his side of the story," she said.

Park's assassination has long been the subject of public fascination in South Korea.

Multiple movies and television dramas have centred around his killing, not least because it orphaned the president's daughter Park Geun-hye -- a future president -- and her siblings.

Park Geun-hye was removed from office in an impeachment over corruption, for which she was later imprisoned.

The reopening of the case also comes as democratic South Korea is mired in political paralysis following the impeachment of President Yoon Suk Yeol, himself charged with insurrection for a failed bid to impose martial law.

AFP

A picture of former South Korean president Park Chung-Hee and his wife is displayed in Seoul at a photo exhibit on the dictator's 1979 assassination — File pic by AFP

South Korean court reopens case of former president's killing