The US Securities and Exchange Commission can seek the South Korean government’s assistance to question Do Kwon’s Terraform Labs co-founder, Daniel Shin, and collect evidence from payments company Chai Corp., a US judge ruled.

The SEC wants to question Shin and get documents from Chai to help prove its suit accusing Terraform and its former chief executive officer, Kwon, of an illegal scheme that wiped out at least $40 billion worth in crypto value. US District Judge Jed Rakoff on Thursday said the SEC can use a process dictated by a 1970 treaty governing requests to gather evidence internationally.

Kwon, who is currently serving a four-month sentence in Montenegro for traveling on a fake passport, is facing criminal charges in both the US and his native South Korea as well as the SEC suit. Kwon and Terraform, who have denied wrongdoing, didn’t oppose the SEC’s request and have included their own requests for evidence to defend the case.

Shin was charged by South Korean prosecutors in April. His lawyer said at the time that he had nothing to do with Terra’s collapse.

Kwon and Shin co-founded the company that became Chai, and it originally shared office and staff with Terraform. The two companies split in 2020, with Kwon becoming Terraform’s CEO and Shin staying at Chai as CEO.

The SEC alleged in its suit that Kwon falsely claimed that Chai used Terraform’s blockchain and its TerraKRW stablecoin to process millions of retail transactions by South Korean consumers. It also claimed that Kwon and Terraform recorded Chai transactions on their blockchain, to make it appear they were using its technology.

In its filing last month, the SEC said it’s seeking testimony and documents about how Chai processed payments, its use of Terraform’s blockchain and stablecoin, communications between the two companies and disclosures to Chai investors about the relationship.

The SEC case is Securities and Exchange Commission v. Terraform Labs Pte., 23-cv-01346, US District Court, Southern District of New York (Manhattan).