In a rare public message on the Cho Kuk issue, Moon pointed out that a strict probe is under way over suspicions connected with the minister, according to Cheong Wa Dae spokesperson, Ko Min-jung.

Cho's wife, a professor, has been indicted on charges of fabricating a college president's citation for use in her daughter's medical school application. Cho's family also faces a probe over their dubious investment in a private equity fund. The minister denies all of the allegations.

"Whether Minister Cho Kuk should be held responsible will be determined by judicial procedures, including the prosecution's investigation," the president was quoted as saying.  

Moon then urged state prosecutors to remember the reality that public demand is growing for reform of their powerful organization.

He called for the reform of not just the system but also the "way of exercising the prosecution's rights and investigative practices," according to Ko.

In particular, it is important to "exercise restrained prosecution rights" to respect human rights, Moon added.

The president's message followed a disclosure that the minister made a phone call to the head of the prosecution team when prosecutors raided his house for investigation into the scandal on Monday.

A lawmaker with the main opposition Liberty Korea Party raised the issue during a parliamentary interpellation session Thursday and Cho admitted that he had such a phone conversation.

The minister said it was not intended to affect the team's field operation, and that he just asked for help in getting his wife to relax.

The LKP claimed that Cho deserves impeachment for the phone call itself as he was apparently abusing his power as justice minister.

The ruling Democratic Party, however, focused on taking issue with what it calls an inappropriate connection between the prosecution and the conservative opposition party.

The DP views both the LKP and the prosecution as bent on forcing Cho to quit in order to block reform of the prosecution.

On the timing of making public Moon's remarks on the prosecution, meanwhile, a Cheong Wa Dae official said there's "no special reason."

"There have been many press queries on the matter," the official said. (Yonhap)