The Wolsong-1 nuclear reactor was shut down earlier than scheduled on the grounds that its economic value was low, but a state audit agency found that it had been unreasonably undervalued.

As the prosecution stepped up investigations into the alleged undervaluation and the obstruction of the audit, leaders of the ruling Democratic Party and Justice Minister are pressing for a stop to the probe.

DP Chairman Lee Nak-yon said Friday that the “prosecution must stop its dangerous and reckless probe immediately.”

He criticized the prosecution of “abusing its authority” and called the investigation “politically motivated.”

DP Floor Leader Kim Tae-nyeon said that the prosecution is “intervening in state affairs.”

Justice Minister Choo Mi-ae said Thursday that Prosecutor General was pushing a “biased and excessive investigation to shake the current government politically.”

Their pressure on the prosecution is a blatant intervention in the legitimate investigation. Their argument is unconvincing.

The prosecution launched an investigation because it received related audit results and official accusations.

On Oct. 22, the opposition People Power Party charged 12 figures involved in the economic valuation with abuse of authority and other crimes.

It is reasonable for the prosecution to launch an investigation if it suspects illegality in the accused.

The party made the accusations based on the Board of Audit and Inspection’s findings, announced on Oct. 20, that the economic viability of Wolsong-1 was unreasonably undervalued in a previous assessment.

The prosecution raided the Ministry of Trade, Industry and Energy and Korea Hydro & Nuclear Power Co. on Thursday and Friday.

The raid was possible because the court issued most of the search and confiscation warrants that it requested. This means that it acknowledged the necessity of investigation.

In fact, the investigation stands to reason, regardless of the PPP’s accusations. The BAI report raises many suspicions of criminal offenses, including the systematic destruction of documents. If the prosecution dawdled on the case, it would be a dereliction of duty. The BAI referred “700-pages of references for investigation,” separately from the audit report, to the prosecution. This is as good as a request for investigation.

Manipulation of Wolsong-1’s economic value is a grave crime by the government. The 700 billion won ($626 million) spent to extend its lifespan went down the drain, and a huge amount of energy to be generated vanished, too. This happened for only one reason: the president’s policy to phase out nuclear energy.

The ministry and KHNP were found to have done an about-face after President Moon Jae-in asked when Wolsong-1 would be closed for good. Before his question, they planned to keep operating it. They first decided to shut it down, then manipulated data to justify the decision.

The prosecution must clarify illegal acts and unreasonable instructions in the run-up to the decision to close Wolsong-1 early.

The board also found that the ministry destroyed 444 documents after it launched an audit. Those found responsible must be strictly punished.

The prosecution would neglect its duty if it does not investigate this obvious crime. It is an obstruction of justice to try to stop the investigation.

The ruling party argues that the government’s energy policy cannot be evaluated only economically and that a policy-making process cannot be investigated.

But even a government policy must be formulated and implemented according to statutory procedures and regulations.

The prosecution’s investigation is a legitimate act of enforcing the law. It is right for the ruling party to call for a strict investigation, but it is shaking the rule of law by trying to block the probe. It is probably doing so because it has many things to hide.

Choo argued that the investigation deserves little consideration even though the opposition party filed accusations. She also said that she would consider doing something about the investigation at an appropriate time as a supervisor if needed.

Her remarks raise concerns that she will command investigation directly or break up the investigation team when it gets closer to the whole picture of manipulation and cover-ups.

If Choo reassigns the case or reshuffles the investigation team to obstruct the probe, she will be condemned for impairing the independence of the prosecution. Anybody who blocks a legitimate investigation must take legal liability.