The controversy over the resignation of former Prosecutor General Chae Dong-wook has been rekindled as a Cheong Wa Dae official was found to have been involved in the illegal perusal of personal information about a child alleged to be the top prosecutor’s illegitimate son.

Chae denied the allegation, raised by a Korean daily in September, that he had fathered a son out of wedlock. But he resigned as head of the Supreme Prosecutors’ Office, saying that such allegations made it difficult for him to carry out his duties.

The Presidential Office said Wednesday it had discovered that in June a director in charge of facility management had asked a senior official at the Seocho-gu Ward Office in southern Seoul to check personal information about the child and had received information about the boy’s family from him.

Senior presidential press secretary Lee Jung-hyun quoted the Cheong Wa Dae official as saying that he acted at the request of an official of the Ministry of Security and Public Administration, who was one of his old acquaintances.

But Lee did not offer an explanation as to why the ministry official sought to obtain personal information about the child. He said prosecutors would dig up more details about the case.

But Lee firmly denied the suggestion that the facility management director, who was removed from his position, may have been acting on behalf of higher-level Cheong Wa Dae officials. Trying to play down the case, Lee described the official’s behavior as a “personal aberration.”

Lee’s explanation is hardly convincing. The fact that a middle-level Cheong Wa Dae official was involved in the illegal leak of personal data about the child fuels the suspicions that the Presidential Office might have been involved in a clandestine operation to take out Chae.

This is the scenario put forward by the main opposition Democratic Party. DP lawmakers allege that Cheong Wa Dae sought to remove Chae from office as he pushed prosecutors to expand their investigation into the National Intelligence Service for tampering with last year’s presidential election.

They note that the dismissed facility management director’s immediate senior is Lee Jae-man, presidential secretary for general affairs, who is one of President Park Geun-hye’s most trusted longtime aides.

Now, prosecutors need to go deeper to determine whether there really was a plot against Chae and, if there was, whether the Presidential Office was involved in it. They should also find out how information about the child was leaked to the Korean daily.

The case offers the first major test for the newly appointed prosecutor general, Kim Jin-tae. He should investigate the case without any political considerations.