SEOUL, A close associate of Terraform Labs co-founder Do Kwon arrived in South Korea on Tuesday following extradition from Montenegro to face an investigation into the massive crash of the cryptocurrency firm that wiped out nearly 50 trillion won (US$37.5 billion) in market value. Han Chang-joon, the 37-year-old chief financial officer of Terraform Labs, boarded a flight from Istanbul at 4:20 a.m. and landed at Incheon International Airport at 2 p.m., before being taken to the Seoul Southern District Prosecutors Office for investigation. Han, masked up and his handcuffed hands covered by black cloth, did not respond to questions by reporters asking whether he had predicted the cryptocurrency implosion, or what he did with the proceeds of the crime. Earlier, Montenegrin officials announced they had handed Han over to South Korean authorities. Han was detained with Do Kwon in March last year at Podgorica Airport after attempting to travel to Dubai with forged passports. The justice ministry has since reque sted their extradition and has cooperated closely with authorities in Montenegro. The extradition of Kwon, who is currently at a detention facility in Montenegro, will be decided before Feb. 15, when his detention is due to expire. "We thank the Montenegro authorities for cooperating with the extradition of Han Chang-joon," the justice ministry said, while vowing to keep working toward the successful extradition of Do Kwon, the key suspect in the Terraform Labs case. The prosecution plans to question Han on the entire process covering the issuance of TerraUSD and its sister coin Luna, and how they tumbled. TerraUSD was designed as a stable coin, which was pegged to stable assets like the U.S. dollar, but its value plunged as low as 10 cents in May, breaking its 1-to-1 peg with the U.S. dollar. Source: Yonhap News Agency