When a Los Angeles internet entrepreneur decided that his company should lend money to Alexander Smirnov, an Israeli American businessman fluent in four languages, he did so in part because Smirnov boasted of a highly respectable background.

“He was representing himself as working for the FBI,” Dmitry Fomichev recalled in an interview about the 2012 loan, which Fomichev would later say in a lawsuit Smirnov never repaid. “He said, ‘I’m a very powerful guy.’”

Several years later, Smirnov again disclosed his work with law enforcement to investors who put up $100,000 in cash for a company he was touting called Grand Pacaraima Gold Corp., the investors later alleged in a suit of their own against Smirnov.

It was true: Smirnov was a source for the FBI. But as a confidential informant, he wasn’t supposed to be broadcasting his government work, and experts and former agents said his apparent decision to do so raises significant questions about his credibility.