A former chief prosecutor said Saturday that presidential candidates should not politicize the issue of investigative rights of the prosecution and police as campaign pledges ahead of the December election.

Former Prosecutor-General Kim Joon-gyu stepped down from his post in July 2011 in protest over the parliamentary approval of a contentious bill that prosecutors claim limits their investigatory power. The resignation came less than two months before his term was scheduled to end in mid-August.

"It is undesirable that the dispute over investigative rights of the prosecution and police is emerging as a hot-button issue during an election period (for the Dec. 19 presidential election)," Kim said in an interview with news Y, Yonhap News Agency's all-news cable channel.

The prosecution and police initially reached a compromise under government mediation to end the dispute over investigative rights, agreeing to empower police to open investigations under the broad supervision of prosecutors.

But lawmakers on June 30 passed a revision of the criminal procedural law that could allow police to open investigations on their own while weakening prosecutors' previously tight grip on police probes.

"The issue of investigative rights is not something that should be defined by politics or decided based on popularity," Kim said. "It is better to discuss the issue after the new president is elected."

How to coordinate investigative authority between the prosecution and police has resurfaced recently as major presidential candidates have addressed the issue as part of their campaign pledges to reform the prosecution.

Ruling party presidential candidate Park Geun-hye, in a news conference last week ahead of Police Day, said there is a need for "a logical separation of roles based on the principle of checks and balances between police and the prosecution."

Moon Jae-in, the main opposition Democratic United Party candidate, has been more active in expanding investigative authority for police. During his visit to a Seoul police station last week, Moon said the law should be changed in the direction of granting investigative rights to the police while having prosecutors devoted to the process of indicting.

Independent presidential candidate Ahn Cheol-soo has also expressed his support for reform measures, such as forming an "independent investigation team" which handles corruption involving public officials.

Kim, the former prosecutor-general, also questioned efforts by political parties to push forward a series of prosecution reform measures, including scrapping the central investigation unit of the Supreme Prosecutors' Office, an elite investigation team which handles large corruption cases.

"Political parties are discussing the abolishment of the SPO's central investigation unit while saying they will also battle corruption," Kim said. "If the division is abolished, who would benefit?"

"I am skeptical as to whether a new investigative unit specializing in the probe of high-ranking officials or a special counsel would function better than the central investigation unit," Kim added.

After leaving office, Kim opened his own law firm and started practicing early this year. He recently published a book titled, "New Initiative on International Cooperation in Criminal Justice." (Yonhap News)