President Park Geun-hye has suffered another major personnel appointment debacle. On Wednesday, her prime minister nominee, Ahn Dae-hee, announced his withdrawal. It was six days after he was picked to head the Cabinet.

The former Supreme Court justice was Park’s second nominee for the No. 2 post of the executive branch to drop out of the process even before his qualifications were verified in a confirmation hearing.

In January 2013, former Constitutional Court chief Kim Yong-joon withdrew his nomination for prime minister in the face of allegations of real estate speculation and other ethical lapses.

Ahn’s dropping out dealt a staggering blow to Park, as his nomination was the first step in reshuffling the Cabinet in the wake of the Sewol ferry tragedy, which had pummeled public confidence in her administration.

Park sought to regain public trust by reforming the civil service and rooting out corruption among public officials. Ahn was seen as the right man for this task, as he was once called “the people’s prosecutor” for his no-holds-barred crackdown on corruption.

But Ahn was no longer a tough-minded prosecutor with high moral and ethical standards. He turned out to have earned 1.6 billion won ($1.56 million) in less than six months since opening a law office last July. His income was far above normal levels.

Ahn was suspected of having benefited from “jeon-gwan-ye-u,” a widely denounced abnormal practice in the legal community. It is characterized by lawyers who used to be judges and prosecutors receiving special treatment from their incumbent former colleagues.

This malpractice motivates clients to prefer lawyers who have previously served as high-ranking judges or prosecutors, as they are perceived to be able to influence rulings in litigations. As a result, these lawyers tend to be entrusted with more cases and command higher fees than their competitors.

As criticism over his behavior mounted, Ahn offered to donate 1.1 billion won. But it was of no use. He could not refute the argument that he was not qualified to spearhead an anticorruption drive because he himself had benefited from a corrupt practice.

Ahn’s withdrawal highlighted the presidential office’s inability to learn a lesson from the repeated personnel appointment debacles. The office must have performed a background check on the nominee and learned of his income in 2013.

The problem was that it did not occur to the vetting officials that Ahn’s large income did not fit his image of a man of high integrity and morality and therefore could cause a problem.

Now that Ahn has resigned, Park needs to pick a new nominee. She has to rush as she reportedly intends to appoint new ministers on the recommendation of the new prime minister in compliance with the Constitution.

In looking for a replacement, Park is strongly advised to refrain from choosing a candidate from among members of her narrow inner circle. She needs to cast a wide net to broaden the candidate pool.

And she should have the presidential office conduct a thorough background check on the new nominee to avoid another fiasco.

The latest row over Ahn’s nomination has again brought into sharp relief the “jeon-gwan-ye-u” practice. The government has sought to eradicate the unwholesome tradition as it erodes public confidence in the nation’s legal system.

But Ahn’s case has demonstrated that it remains firmly in place. The government should renew efforts to eradicate it, as it is another form of the widely criticized cozy relationship between former and incumbent public officials.