The man, who is in his 60, was identified in local media reports only by his surname, A.
He has a standing arrest warrast for 10 charges relating to the alleged cryptocurrency scam, including fraud.
The man has since been handed over to the Seoul Southern District Prosecutors’ Office, which has been leading the investigation against him.
Rising cryptocurrency-related crimes have prompted concern from governments across the world.
According to blockchain analytics firm Chainalysis, cryptocurrency platforms lost $2.2bn to theft in 2024, while illicit actors received an estimated $40.9bn in cryptocurrency.
Last year, South Korean police arrested more than 200 people for allegedly stealing $240m – in what is believed to be the country’s largest cryptocurrency investment scam.
Additional reporting by Hosu Lee in Seoul