Investor, "Shark Tank" judge and CNBC contributor Kevin O'Leary said Thursday he's lost all of the $15 million FTX paid him to act as a paid spokesman for the now collapsed crypto exchange that some have called fraudulent.

O'Leary and other celebrities, such as Tom Brady and Larry David, were sued by FTX investors who say the exchange's ambassadors should have done more due diligence and exercised a greater level of care before promoting the crypto empire.

The Canadian investor was grilled by CNBC's "Squawk Box" hosts over his failure to properly assess the risks associated with investing and promoting FTX. O'Leary said he fell prey to "groupthink," and that none of his investment partners had lost money.

"Total deal was just under $15 million, all in," O'Leary said Thursday morning on CNBC's "Squawk Box." "I put about $9.7 million into crypto. I think that's what I lost. I don't know. It's all at zero."

O'Leary also said he had over $1 million of FTX equity, now rendered worthless by the bankruptcy protection process. The balance of a little over $4 million was purportedly eaten up by taxation and agent fees, according to O'Leary.

O'Leary promoted FTX aggressively on Twitter and online, touting his close connection with disgraced founder Sam Bankman-Fried, who is facing multiple investigations.

When O'Leary first began to promote FTX, he said it was FTX's compliance systems that drew him to invest in the crypto exchange.

"Finally solved my compliance problems with #cryptocurrencies," O'Leary wrote on LinkedIn and in a since-deleted August 2021 tweet.

Eventually, Delaware bankruptcy protection filings by new FTX CEO John Ray would term FTX's risk, audit and compliance procedures "a complete failure of corporate controls."

"It was not a good investment," O'Leary said Thursday.