The major crypto lender Nexo has been hit by a tsunami of customer withdrawals after the company’s office in Bulgaria was raided by police.

The raid at Nexo’s Sofia, Bulgaria office happened on Thursday at more than 15 sites across Sofia, Reuters reported. It added that more than 300 investigators, police and security officers were involved in the operation.

Nexo is being investigated for fraud, money laundering and tax evasion, multiple media outlets have reported. In a statement from the Bulgarian Prosecutor’s Office, Nexo’s business was referred to as “an illegal criminal activity.”