The prosecution said Sunday it is looking into allegations the state intelligence agency set up plans to control the management of major broadcasters in the late 2000s.
The National Intelligence Service was also found to have compiled a blacklist of senior officials and program directors critical of the conservative government according to its internal inspection.
The prosecution is widening its probe into past wrongdoings by NIS officials involved in political smear campaigns and gagging dissident cultural figures under two conservative governments from February 2008 to March 2017.
An NIS special committee launched by the liberal Moon Jae-in government is also conducting extensive probes into alleged political meddling, abuse of power and human rights violations by the spy agency.
The NIS panel recently handed to the Seoul Central District Prosecutors' Office a raft of documents which contain NIS plans to change the leadership at major TV networks in 2009. It advised the government to replace them by having executives tender their resignations in masse and selectively receive them.
In December 2009 MBC President Ohm Ki-young and other senior officials offered to resign. He was replaced by a figure close to the government.
The documents indicated the NIS had checked the political stances of a number of executives of public broadcasters and interfered with their personnel changes.
The probe panel also found documents that suggest the NIS created and managed a watch list of program makers and employees unfriendly to the government.
In 2010 the agency pressured a broadcaster to drop a documentary made by a listed director from an annual awards show, according to the records. A radio program director on the list was assigned to a position in a regional branch that year.
The prosecution plans to look into whether the plans were executed, which would constitute abuse of power and the violation of its duty of political neutrality.
The prosecutors last week started an investigation into allegations that then NIS chief Won Se-hoon and other NIS officials managed a blacklist of artists and cultural figures unfriendly to the Lee government.
On Friday, the ruling party called for a parliamentary probe into alleged attempts by the former governments to control local broadcasters.
All of the 121 Democratic Party lawmakers signed a motion requesting the investigation into 37 cases involving the two administrations.
Among the cases are purported political moves to meddle in the operations of three major broadcasters -- KBS, MBC and YTN -- and those involving journalists thought to have been unfairly sacked due to their political views. (Yonhap)