The South Korean government apparently has agreed to cooperate with the House ethics committee in its investigation of alleged Korean influence buying on Capitol Hill.

Rep. John J. Flynt (D-Ga.), chairman of the committee, told other members yesterday that he had received "assurances of cooperation from a foreign embassy." But he declined to elaborate on the remark after the meeting.

"I probably misspoke-myself there," he said. Asked if he was referring to the South Korean Embassy, he said, "I can't say anymore about it, because it's an element of an ongoing investigation."

Earlier yesterday, tht House Rules Committee cleared the way of a full House vote Wednesday on a Flynt resolution directing his committee to make a full investigation into reports that members of Congress accepted cash and gifts from representatives of the South Korean government.

A spokesman for the Korean Embassy said yesterday that his government would cooperate fully with any U.S. investigation of the allegations. "within the protocols of these two friendly nations." He also declined to answer further questions.

Senior embassy officials are protected by diplomatic immunity from being subpoenaed by investigators. The resolution approved by the Rules Committee yesterday would give the ethics committee additional powers to take depositors and sworn interrogatiories from witnesses - including diplomats who agreed to do so voluntarily.

Before forwarding the resolution to the full House, members of the Rules Committee asked Flynt and his cosponsor, Rep. Floyd D. Spence (R-S.C.), several pointed questions about the scope of the inquiry.

Reps. B. f, Sisk (D-Calif.) and John Joseph Moakley (D-Mass.) both said they deplored published reports citing estimates that from 50 to 100 members of Congress were involved.

Flynt said in response that he had uncovered no evidence to support such figures. In fact, he read a letter from Sen. Howard Baker (R-Tenn.) in which the Senate minority leader said his recent televised statement about "40 to 50" members being involved was based on nothing more than what he's read in the papers.

"With that kind of technique, it sounds like we've got another Tial Gunner Joe," Moakley said, referring to a television show about the late Sen. Joseph McCarthy's inprecise hunt for Communists in government in the 1950s.

In answer to other questions, Flynt said he would investigate the conduct fo former as well current members, make periodic reports to the House and hold open hearings as soon as poissible.

At his own committee meeting yesterday afternoon, Flynt ran into opposition from Rep. James Quillen (R-Tenn.) over the latitude the committee was giving special counsel Philip A. Lacovara.

Quillen protested the language in a committee resolution might allow the former assistant Watergate special prosecutor to "go on a whitchunt" beyond the control of the committee. But Flynt said he did not want to "tie the hands" of Lacovara by requiring committee approval of every witness to be interviewed.

Flynt's view prevailed.