The Federal Bureau of Investigation is, along with several other U.S. agencies, looking into the downfall of Canadian cryptocurrency exchange QuadrigaCX, and has reportedly reached out to users to know more about their use of the platform.

As Bloomberg reported, the FBI, the Internal Revenue Service’s Criminal Investigation Division, the Department of Justice’s Computer Crime and Intellectual Property Section, and the U.S. Attorney’s Office for the District of Columbia are conducting an investigation.

CryptoGlobe reported earlier this year that QuadrigaCX was locked out of $145 million worth of cryptocurrency it owed customers after the unexpected death of its founder and CEO Gerald Cotten. This saw around 115,000 users lose their funds, with one losing his $420,000 life savings.

The company behind the exchange, Quadriga Fintech Solutions, is in bankruptcy proceedings in Canada. The FBI is reportedly asking users whether they provided identifying information when opening accounts at the Canadian cryptocurrency exchange, and if their transactions were made using U.S.-based financial institutions.

A statement on the agency’s website reads:

The FBI and IRS-CI are legally mandated to identify victims of federal crimes that they investigate and provide these victims with information, assistance services, and resources.

As covered, the Ontario Securities Commission has stated it was looking into QuadrigaCX’s downfall, over its potential to harm investors from Ontario. At the time the regulator noted it was in contact with court-appointed monitor Ernst & Young.

The monitor has also noted that it managed to identify several cold storage wallets QuadrigaCX used. It found that five out of six wallets had been empty since April of last year, with one receiving an inadvertent transfer this year.

Various cryptocurrency enthusiasts have dug into blockchain data to try and found the cryptocurrency exchange’s missing funds. One researcher has claimed to have found $90 million of the missing funds, in wallets belonging to other exchanges.