A prominent opposition lawmaker has been indicted on charges of defaming a younger brother and a former close aide of President Park Geun-hye by raising allegations that they had intervened in presidential affairs, prosecutors said Friday.

Rep. Park Jie-won of the No. 1 opposition New Politics Alliance for Democracy claimed that a group of powerful people -- including Park's younger brother Ji-man and Chung Yoon-hoi, who served as the president's chief of staff when she was a lawmaker -- exerted influence on appointing ranking officials at the presidential office Cheong Wa Dae.

Such remarks were made while the opposition lawmaker was having an interview with the local press on June 25.

Prosecutors at the Seoul Central Prosecutors' Office probing the case said they have indicted Park, a four-term lawmaker, without physical detention.

The opposition lawmaker is further accused of making defamatory remarks against President Park while appearing on the popular online political satire show "Naneun Ggomsuda," roughly translated in English as "I am a Petty-minded Creep," in April 2012.

The lawmaker raised allegations of the president's possible involvement in a massive bribery scandal related to a suspended savings bank on the show.

The legislator claimed that the president met with a key lobbyist for the now-suspended Busan Savings Bank on several occasions, calling on the prosecution to investigate possible irregularities in the course of those meetings.

President Park has denied any ties to the lobbyist, Park Tae-kyu. (Yonhap)