A former CIA agent in South Korea yesterday accused the agency of "deliberately" suppressing information in the early 1970s that U.S. congressman were talking sexual and financial bribes from South Korean officials in exchange for favorable trade arrangements.

"It was a cover-up," the former agent, C. Philip Liechty, charged in an interview. "Internal CIA reports in late 1971 and 1972 had the details, but they were never sent to Washington. The information came into our hands accidentally, [But] it confirmed, what we had been hearing all along."

Liechty, 39, was in the CIA's Seoul office at the time.

Liechty said the unidentified CIA officials who allegedly suppressed the information did so in an attempt "to avoid political embarrassment" with congressional officials. One source close to Liechty said that they CIA feared its budget would be curtailed by vindictive congressmen if the information became known.

"The name of the game was sex and booze and all the good things Asia has to offer," including money, Liechty said.

The former agent, who was fired by the CIA last year during its economy-oriented reduction in personnel, declined to identify congressmen who reportedly took the favors, whose identies were known to CIA officials.

Agents allegedly were told by their superiors in 1971 and 1972 not to ask their Korean sources about wealthy Korean businessman Tongsun Park, who was at the center of the South Korean influence-peddling scandal, the source close to Liechty said.

However a House Foreign Affairs subcommittee has reported that some information on Park's lobbying efforts was reported back to Washington in the early 1970s, but it was not turned over to the Justice Department for possible prosecution until late 1975.

Additionally, the Senate Intelligence Committee, in a 1978 report on the CIA role in the Korean bribery affair, concluded that there was no evidence of an intentional cover-up. The report criticized the agency, however for what it described as sloppy reporting techniques.

Liechty was interviewed by the committee staff shortly before the report was issued a spokesman for the committee said.

Liechty spoke with reporters yesterday after appearing in federal court in Alexandria in connection with a $2 million civil defamation and invasion-of-privacy suit he filed against a former CIA colleague, Robert F. Bodroghy. A deposition Liechty made in the case purportedly contains information about national security matters, and the Justice Department last week had that material placed under seal so it would not be made public.

Yesterday, U.S. District Court Judge Oren R. Lewis declined to rule in advance that any other national security matters revealed in the case be placed under seal. He indicated however, that he probably would do so to protect "national security," if the government filed the proper forms.

Outside the court Liechty, who joined the CIA in 1963, claimed that the agency used a bureaucratic device in the mid-1970s to conceal from the Senate committee the agency's alleged involvement in foreign assassinations, which the intelligence panel then was investigating.

According to Liechty, CIA personnel were ordered to sign a form stating their "direct knowledge" of assassinations. Such language prohibited them from "revealing the detailed but indirect knowledge we had" of CIA involvement, he said. Liechty also insisted that he possesses such "indirect" knowledge, but he would not elaborate.

A CIA spokesman refused to comment yesterday on Liechty's charges.

The former agent said that the "massive bureaucracy that stifled accurate reporting" was what most angered him about the agency.

For example, the source close to Liechty said the ex-agent's reports of alleged torture of South Korean students by Korean government officials were watered down by CIA officials in Seoul before being sent to Washington.

The source added that although Liechty admittedly has no documents to back up his various allegations, he has offered to take lie-detector tests.

The civil suit against Bodroghy stems from a bitter child-custody battle involving Liechty and his wife. Bodroghy allegedly told officials in the custody dispute that Liechty had been fired from the CIA for failure to obey orders and finish reports, and for once threatening with a gun a CIA official who interfered with him, according to court papers.

Bodroghy has declined comment.