On-chain investigator ZachXBT identified the French banking group Cr é dit Mutuel Ark éa as a victim of an alleged crypto theft worth over $133 million, and warned that the total loss could be even higher.

This anonymous crypto detective stated on Wednesday that the institution, which he claimed has an asset size of $235 billion, is said to have been exploited over several days. He also mentioned that in addition to the previous estimates, there may be additional losses from over-the-counter trading ( OTC ).

“I suspect that the amount stolen will be even greater after taking into account the OTC activity,” said ZachXBT.

The claim that the bank is involved in the case has not yet been independently verified, and ZachXBT has not disclosed how the attackers obtained the funds.

Cointelegraph has contacted Cr and dit as well as Mutuel Ark to seek comments, but no response has been received as of the time of publication.

This disclosure follows closely on the preliminary report from ZachXBT on Monday. At that time, he pointed out that the suspicious withdrawal amounts from centralized exchanges had exceeded 106 million US dollars.

On Tuesday, after discovering an additional $27 million in withdrawals, he raised his estimated loss to over $133 million, with some of the withdrawals occurring after he first issued a warning.

Blockchain analytics firm Bitquery previously tracked withdrawals from accounts belonging to Kraken, Crypto.com, and OKX. The firm discovered that approximately $63 million in stablecoins were converted into Ethereum (ETH) within four hours.

Subsequently, Kraken and Crypto.com informed Cointelegraph that they had restricted the relevant accounts or frozen funds suspected to be involved in the theft. Both exchanges stated that their platforms were still secure.

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