Prosecutors on Wednesday detained a man for allegedly signing up on a shady deal to help Cho Hyun-ah, former vice president of Korean Air, receive special treatment during her stay in prison.

The Seoul Southern Prosecutors’ Office detained the 51-year-old man, surnamed Yeom, charging him with illegally securing a deal to do business for Hanjin rental car service in exchange for helping Cho, also known as Heather Cho, to receive preferential treatment as she served out her sentence, officials said.

Hanjin rental car service is an affiliate of Hanjin Group, headed by Cho’s father, Korean Air chairman Cho Yang-ho.

According to the prosecution, Yeom offered to arrange for special care of Cho during her stay in jail after the lowest court sentenced her to one year in prison in February in the so-called “nut rage” case.

The prosecution is probing whether Yeom bribed officials in prison, in return for treating Cho favorably. It is also looking into whether she really enjoyed special privileges while in prison.

Cho, who was in charge of in-flight services of the nation's biggest airlines, served a jail term until May for violating plane safety after she ordered the taxiing flight bound for Incheon, with more than 200 passengers on board, back to the gate at John F. Kennedy Airport last December, taking issue with what she viewed as “poor cabin service.”

Unsatisfied with the way a first-class flight attendant served macadamia nuts, Cho assaulted the plane’s chief steward, made him kneel and struck his hand with a folder.

An appeals court freed her in May, handing down a reduced sentence of 10 months, suspended for two years.

In relation to the brokerage case, investigators raided Yeom’s residence and the office of a high-ranking Hanjin Group official surnamed Seo, who allegedly introduced Yeom to Cho.

Seo and Yeom have allegedly been in a close relationship since they first met in the aftermath of the Korean Air crash in Guam in 1997 that killed 228 people on board. Yeom was a representative for victims’ families back then.

The now infamous “nut rage” case continues to persist despite Cho’s release, with the chief steward and the first-class flight attendant having filed separate lawsuits in the U.S. to seek financial compensation.

By Ock Hyun-ju (laeticia.ock@heraldcorp.com)