Justice Minister Choo Mi-ae and her husband asked the defense ministry in 2017 to extend medical leave for their son who was serving his mandatory military duty at the time, according to documents apparently written by the ministry.

Choo has come under fire over allegations that she used her influence to seek special favors for her son, who served in the Korean Augmentation to the United States Army (KATUSA) for the 2nd Infantry Division of the US 8th Army. Choo was chairwoman of the ruling Democratic Party at the time.

According to the documents seen Wednesday and apparently written recently by the personnel office of the Ministry of National Defense, a then master sergeant in charge of the support team had two meetings with Choo's son regarding his medical leave.

The son, surnamed Seo and now 27 years old, took his first medical leave from June 5-14, 2017, to receive knee surgery, and extended it once through June 23. For four days after that, he used his personal vacation days before returning to his unit. The allegations are that those last days were not approved in advance but he was able to extend his leave without first returning to base thanks to his mother's influence.

"(Seo) inquired about ways to extend his medical leave because he has yet to fully recover," the master sergeant wrote in records of their second meeting, which are summarized in the documents. The records are dated June 15, 2017. The first meeting took place in April.

"(I) had told him before he went on leave that medical leave is permitted up to one month, but (Seo) said he felt bad about asking (me), and while consulting his parents, found out that they had already filed a request," he wrote.

The master sergeant continued, "I told him that he has nothing to feel bad about and firmly requested that he ask (me) directly next time and resolve his questions that way."

The records, if true, indicate that Choo and her husband personally made a request regarding their son's leave with the defense ministry before the first leave ended.

They also show that Seo told the master sergeant that he would send a doctor's note the following week because the doctor was away for business. The master sergeant told Seo to use his personal vacation days until an assessment of medical leave is complete, and when the medical leave is approved for extension, the vacation days would be restored.

Seo's lawyer has made similar claims.

In a statement Tuesday, the lawyer said the second medical leave was first approved verbally, and following instructions, the supporting documents were sent by email on June 21, 2017.

The allegations of preferential treatment have become the latest political football, with the main opposition People Power Party calling on President Moon Jae-in to take a stand, and the Democratic Party dismissing the case as groundless.

Other key allegations surrounding Seo are his family's reported attempt to get him assigned to a base in Seoul, rather than in Uijeongbu, north of the capital, and their reported push to have him selected as an interpreter for the February 2018 PyeongChang Winter Games.

Prosecutors launched an investigation into the alleged preferential treatment in January, but no progress has been announced.

Choo has denied abusing her power to get special favors for her son. (Yonhap)