Military prosecutors today accused the Army's former top officer of having helped the assassin of president Park Chung Hee because he thought the killer might become South Korea's next ruler.

The court martial of Gen. Chung Seung Hwa opened with prosecutors disclosing for the first time their reasons for suspecting him of complicity in the slaying Oct. 26 of the president.

An indictment read in court did not accuse Chung of taking part in any assassination plot. Instead, it charged that he deliberately delayed investigating the assassin in the hours following the killing, thereby abetting the "criminal act."

Chung was Army chief of staff at the time and become martial law commander the morning after the slaying. He was overthrown and arrested by younger officers on Dec. 12, then imprisoned on a vague charge of having helped the assassin.

The former director of the Korean Central Intelligence Agency, Kim Jae Kyu, has been sentenced to death for killing Park in a KCIA dining room. He is appealing to the supreme court.

Chung's role on the night of the killing has been widely suspect here because he was dining near the murder scene and left it in an automobile with Kim, who was not arrested until the following morning.

An official report published while Chung was martial law commander said he actually had played along with Kim's story and subsequently tricked him into being arrested.

The indictment read in court today, however, said Chung actually aided Kim in concealing facts after the murder and purposely delayed an investigation even though he had become convinced Kim was the assassin.

He did so, the indictment alleged, because he assumed the KCIA director had many supporters behind him and "might be the next power" in South Korea.

Chung made a partial troop mobilization after Kim told him martial law had to be imposed and reported his action to him "to show that he was helping him," the indictment said.

At one point, it said, Kim told Chung the future of the country "is on your shoulders."

Even after being told by an eyewitness that Kim had shot the president, Chung did not act against him, the indictment said. He ordered Kim arrested by military personnel only after being told to do so by higher Defense Ministry officials, it said.

Chung, a four-star general, was brought into court in handcuffs this morning. About 60 persons, including five members of his family, attended the trial in a compound of the Defense Ministry.

There has been widespread speculation that Chung will not be sentenced to death or imprisonment for his role. He has many friends among the older South Korean generals, many of whom were also ousted in the intramilitary coup and are still angry over their treatment. Many observers expect Chung to be given a suspended sentence and dismissed from the armed forces.