Microstrategy founder and bitcoin enthusiast Michael Saylor said Silvergate was "responsible" amid the collapse of other crypto institutions including the FTX exchange and said he'd keep doing business with the crypto-friendly bank.

The executive's comments come as the Justice Department’s fraud unit has reportedly begun probing Silvergate’s handling of accounts for former FTX CEO Sam Bankman-Fried’s firms. The fraud probe is focused on potential criminal wrongdoing in allowing FTX’s deposits – including user funds – into accounts belonging to sister trading firm Alameda Research, Bloomberg News reported on Thursday, citing sources.

"We will continue to do business with Silvergate," Saylor said on CNBC. "The institutions that were improperly constructed collapsed — the Alamedas, the FTXes, the Voyagers, the BlockFis of the world — but in fact, Silvergate was a responsible bank."

Last year, Silvergate issued a $205 million term loan to MacroStrategy LLC, a subsidiary of MicroStrategy. 

Saylor also defended cryptocurrencies following comments this week by Charlie Munger, vice chairman of Berkshire Hathaway, who called for a ban on cryptocurrencies in a Wall Street Journal op-ed.

"If he was a business leader in South America or Africa or Asia, and he spent 100 hours studying the problem, he would be more bullish on bitcoin than I am," Saylor said. "The Western elite, they haven't had the time to study it."