An underwear tycoon nabbed in Thailand earlier this week in connection with the prosecutors' ongoing investigation into opposition leader Lee Jae-myung's corruption allegations is willing to voluntarily return home later this week at the earliest, judicial and other officials said Thursday.

   Kim Seong-tae, former chairman of underwear maker Ssangbangwool Group, was apprehended by Thai police at a golf club near Bangkok on Tuesday evening, roughly eight months after he fled the country amid several high-profile corruption investigations.

   Kim has been long sought after by prosecutors as a key suspect in a number of high-profile corruption investigations, including alleged payment of Lee's attorney expenses by proxy, suspected embezzlement of company funds and alleged transfer of cash to North Korea.

   Kim's extradition was previously expected to take a long time, as he reportedly denied illegal stay soon after arrest and was expected to start a litigation to delay his deportation.

   Contrary to the expectations, however, Kim has revealed to the authorities that he will return to South Korea voluntarily, the officials said.

   Kim has reportedly chosen his voluntary departure due to concerns about the inferior environment of the Southeast Asian country's detention facilities.

   "Kim may have decided that there would be no actual benefits for him to file a lawsuit to refuse repatriation," a group official said.

   "If an emergency passport is issued, he will be able to go through immigration procedures and board a flight tomorrow at the earliest before arriving here Friday or Saturday," the official said.

   Kim resigned as group chairman in 2021 but has allegedly remained in charge of major decision-making at the group.

   A Thai court reportedly sentenced Kim to a fine earlier in the day after hearing his position and the immigration office is said to have decided on his deportation and is in the process of carrying out related procedures.

   With his passport canceled, Kim is expected to receive an emergency passport or temporary travel document before departing for Incheon International Airport, west of Seoul. (Yonhap)