In what is apparently the final action in the long-running Justice Department investigation of South Korean influence buying in Congress, a federal grand jury here yesterday indicted former represtative Nick Galifianakis (D.N.C.) on charges he lied to Congress about taking $10,000 in cash from Tongsun Park.

The grand jury also charged another Korean-born Washington businessman, Hancho C. Kim, with contempt of Congress for refusing to answer a question about $600,000 in cash he allegedly received from the Korean CIA to influence members of Congress.

Department attorneys also were known to have considered seeking a perjury indictment against Rep. Edward Roybal D-Calif, but apparently have decided against it.

United Press International reported last night that a Justice lawyer told a US magistrate to dismiss the grand jury because, "It is unlikely they will be needed again."

Galifianakis is the third former House member indicted in connection with the South Korean government's well-documented effort to ensure continued US aid by giving cash and gifts to elected officials.

The former three-term congressman was charged with lying during an appearance in March 1978 before the House committee investigating the scandal. He denied then that he received $10,000 in cash from Park in November, 1972 during his unsuccessful campaign for the US Senate.

Both Park and his secretary, Barbara Fletcher, testified, however, that Galifianakis got the money.

Neither Galifianakis nor his Washington attorney, Seymour Glanzer, could be reached for comment yesterday.

Kim was indicted on a misdemeanor charge for failing to answer the same question from House investigators last May that led to his indictment and perjury conviction. His attorney, David Povich, said yesterday he will soon file court papers "addressing the propriety of charging him again for the same thing."

Kim was convicted last May of perjury and conspiring to pass $600,000 to members of Congress. The government never alleged that he actually made any cash payments, as Tongsun Park did.

A naturalized American citizen from Lanham, Md., Kim is preparing to serve a six-month prison term on that conviction. He also pleaded guilty and has fined $10,000 on a related income tax evasion charge.

Retired representative John J. Flynt (D-Ga.), then chairman of the House Committee on Standards of Offical Conduct, said when the House voted the Kim contempt citation that he realized his investigators' question put Kim in an untenable position. But he said there was no excuse for not answering a congressional committee.

No current member of Congress have been indicted in the investigation. The two other former members charged were Richard Hanna D-Calif.) and Otto E. Passman (D-La.).

Hanna pleaded guilty to conspiring with Tongsun Park to take bribes in return for his help in getting Korean and US government help for Park's rice sales business. Hanna is now serving a prison sentence.

Passman was acquitted earlier this month by a Louisiana jury of charges that he took bribes form Park in return for his help in promoting Park's rice business.