Prosecutors looking into the crash of the cryptocurrency Luna have banned Terraform Labs employees from leaving the country.

According to various legal sources on Tuesday, the Seoul Southern District Prosecutors’ Office has levied a one-month foreign travel ban on all workers at Terraform Labs as it investigates claims of fraud.

The prosecution plans to summon all employees for questioning, focusing on the development process of Luna and its associated algorithmic stablecoin TerraUSD. The development of a loan platform service, the “Anchor Protocol,” will also be investigated.

If the employees are charged with fraud, the prosecution may summon Terraform Labs founder and CEO Do Kwon by invalidating his passport, or it may conduct an investigation by raiding his suspected offices operating in the country under borrowed names.

Kwon has reportedly been residing in Singapore since last year.