Prosecutors asked Thursday for the postponement of a court sentencing of a former state intelligence agency chief accused of meddling with the 2012 presidential election, as they have reopened an investigation into the scandal.

Sentencing for former National Intelligence Service Director Won Sei-hoon is scheduled for Aug. 30. Won has been on trial for allegedly pulling the strings of secret operations to use Internet comments to sway voters in favor of then-conservative candidate Park Geun-hye against then opposition candidate Moon Jae-in.

Park won the vote by a thin margin and took office as president in early 2013. But less than four years into office, she was impeached and ultimately ousted from office over a massive corruption scandal. Moon was elected the new president in May's presidential election.

Prosecutors reopened the investigation into the election meddling scandal after an internal probe of the NIS found the agency ran 30 such "cyber teams" involving Internet-savvy civilians for election-meddling operations.

Officials said that Won's sentencing should be put off as more evidence is coming.

"After the hearings are over (in Won's trial), the NIS announced the results of its inspection and referred people for investigation. The prosecution has launched an additional investigation, raiding locations and summoning people," a prosecution official said.

"The scope of civilian teams (used in election-meddling operations), which had not been fully known, has been confirmed and this needs to be reflected in the trial," the official said of the need to postpone Won's sentencing.

It is up to the court to decide whether to accept the prosecution's request or not.

Prosecutors have banned the 30 leaders of the election meddling teams as well as former and incumbent NIS officials suspected of involvement in the scheme from leaving the country. Investigators are tracing bank accounts to track down the money flow between the agency and the secretive teams.

Depending on the results of the investigation, prosecutors could press additional charges against Won.

Another focus of the probe is how far it will go, including who else, in addition to the former NIS chief, will be investigated.

Some even speculate that top officials of the government of former President Lee Myung-bak, the predecessor of Park, could be targets. (Yonhap)