The United States Federal Bureau of Investigation (FBI) called for former users of the QuadrigaCX cryptocurrency exchange to provide information in an official announcement published on June 3.

Earlier this year, QuadrigaCX had filed for creditor protection after the unexpected death of its founder left more than $145 million in funds apparently inaccessible.

The FBI announcement asks people who lost funds due to the insolvency of the exchange in question to fill in a questionnaire asking about various details concerning their experience with the company and personal data:

“If you have questions or concerns about your QuadrigaCX account, or if you believe you are a victim, please complete the below questionnaire. [...] Based on the responses provided, you may be contacted by the FBI and asked to provide additional information.”

The form itself asks former QuadrigaCX users for their usernames and whether they have access to the addresses of the exchange’s hot wallets and old transaction IDs. The questionnaire also asks whether the respondents provided document scans and identifying information to the exchange, and what funds they held in their account. The FBI notes that those that respond to the survey may be asked for additional information that could be useful in the investigation.

As Cointelegeraph reported in May, a new report from Big Four audit firm EY outlined the assets and debts of major Canadian crypto exchange QuadrigaCX and its subsidiaries, revealing that Quadriga has around $20.8 million in assets and around $160 million in liabilities as of April 12, 2019.

Separately, an April 30 indictment of two individuals on multiple counts — including bank fraud and operating an unlicensed money transmitting business — showed an apparent connection to the shadow banking services that were used in two recent high-profile crypto exchanges, one of which being QuadrigaCX.