A former general-turned-president of South Korea gave a tacit nod to a 1973 secret operation to kidnap Kim Dae-jung, then a dissident leader who later became the country's first opposition-backed president, a government panel said on Wednesday.
The fact-finding panel of the National Intelligence Service (NIS) also said it cannot rule out the possibility that former South Korean President Park Chung-hee may have directly ordered the kidnapping of Kim, then his main political archrival.
"It is judged that there was at least an implicit permission" from Park, the panel said in its investigation report.
It marked the first time South Korea's government has acknowledged Park's involvement in the kidnapping, although many South Koreans have believed the military-backed leader, who ruled the country for 18 years with an iron fist after a 1961 coup, was behind it.
The NIS panel was set up in 2004 as part of a government drive to shed light on long-running suspicions involving the spy agency that former authoritarian rulers of South Korea are accused of using to oppress dissidents and for other political purposes.
The panel, however, did not draw a clear conclusion on whether the kidnapping was ultimately aimed at killing Kim.
Secret agents of the then Korean Central Intelligence Agency kidnapped Kim from a Tokyo hotel on August 8, 1973, just days before he was to launch a coalition of Japan-based South Korean organisations to work for their country's democratisation.
Kim, then 47, was a serious challenger to Park's dictatorship, nearly defeating Park in a 1971 presidential election.
After the stunning election outcome, Park revised the constitution to guarantee himself victory in future elections.
Kim has said his abductors nearly dumped him from a ship at sea a few days after the kidnapping, but stopped when a US military helicopter made a low pass over the vessel.
He was brought to Seoul on August 13 and put under house arrest.
Any US role in saving Kim was unclear.
But former US Ambassador Donald Gregg, who worked as an intelligence officer in Seoul at the time, was quoted as saying in a 1998 newspaper
interview that the then US ambassador visited Park and asked for Kim's release.
The abduction briefly chilled South Korea's relations with Japan.
But Tokyo later agreed to a South Korean effort at a political settlement of the case, saying it expected Seoul to get to the bottom of the incident.
The fact-finding panel blamed Japan for cooperating with South Korea to cover up the kidnapping.
"Japan's government could have noticed the involvement of South Korea's government (in the kidnapping), but cooperated in a diplomatic settlement," the panel said in its investigation report.
In response to the findings, Japan's Prime Minister Yasuo Fukuda said that it is "truly deplorable that Japan's authority was violated."
Park was murdered by his own spy chief in 1979.
His successor, Chun Doo-hwan, took power in a military coup.
His junta pressed trumped-up sedition charges against Kim in 1980 over a pro-democracy uprising in Kim's home province.
A military tribunal sentenced Kim to death, but he was allowed to leave for exile in the US in 1982.
Twenty-five years after the abduction, Kim was elected president in 1997, the first South Korean opposition leader to come to power.
Kim won the 2000 Nobel Peace Prize for his reconciliation drive with North Korea.