A South Korean man accused of being responsible for a cryptocurrency crisis which cost investors $40bn (£31.8bn) has finally been extradited to the United States.

Do Kwon was the boss of Terraform, which operated two cryptocurrencies – TerraUSD and Luna – both of which collapsed in 2022, sparking a wider sell-off in the crypto market.

The US says he was responsible for the coins’ failure, accusing him of “orchestrating a multi-billion dollar crypto asset securities fraud”.

Kwon fled South Korea after a warrant for his arrest was issued, eventually ending up in Montenegro where he has now been extradited from, following a lengthy legal battle.

He was previously found guilty of forging documents by a Montenegro court, having been arrested as he was attempting to board a plane to Dubai in March 2023.

It had been unclear whether he would face criminal proceedings in the US, however, as Montenegro does not have extradition treaties with the US or South Korea, which has also been seeking his extradition.

Kwon finally being sent to the US brings to an end legal proceedings that lasted more than 18 months.

The Montenegrin Ministry of Justice approved the extradition earlier in December.

It claimed that Do Kwon had also agreed to it.

Kwon’s firm Terraform Labs became widely known in 2021, when its coins Luna and TerraUSD exploded in popularity.

Fans of Luna became known as “Lunatics”, with Kwon referred to as their “king”.

But, despite a huge amount of money being poured into the coins, on 9 May 2022 Terraform Labs collapsed catastrophically, losing more than 99% of its value in 48 hours.

Investors scrambled to take their money out of other cryptocurrencies, fearing that a similar thing could happen to them, which resulted in values falling significantly across the whole sector.

It’s estimated the so-called “cryptocrash” resulted in losses of $400bn (£318 bn).

Bitcoin was among the assets affected, however it has significantly grown in value since then and briefly stood at more than $100,000 per coin in December.

Terraform Labs ultimately filed for bankruptcy in the US in January 2024.