Onchain investigator ZachXBT has identified French banking group Crédit Mutuel Arkéa as the alleged victim of a crypto theft exceeding $133 million, warning that total losses could be higher.

On Wednesday, the pseudonymous crypto sleuth said the institution, which he described as having $235 billion in assets, was allegedly exploited over multiple days. He also suggested that additional losses may have occurred through over-the-counter (OTC) transactions that were not included in earlier estimates.

“I suspect the amount stolen is larger when accounting for OTC activity,” ZachXBT said.

The bank’s alleged involvement has not been independently verified, and ZachXBT has not disclosed how the attackers gained access to the funds.