Citron Research's Andrew Left, who gained notoriety for successful bets against companies such as Valeant Pharmaceuticals, called Ubiquiti Networks a "fraud" during a televised interview Monday.
"The word 'fraud' I use very judiciously," the short-seller said in an exclusive interview on CNBC's "Halftime Report."
"I think when you look at all these red flags it doesn't take a CFA, you don't have to go to a top business school, you sit down and read the Citron report, and you'll conclude, 'Oh my God, this company must be a fraud," he added.
The company makes wireless networking products. Its CEO is Robert Pera, majority owner of the Memphis Grizzlies.
Left said it will be interesting to see what happens next month when Pera has an option to buy the rest of the NBA team, which will require more due diligence on his company by the league.
"The more sunlight you put on a fraud, the more chance it has of being exposed," Left said.
Shares of Ubiquiti plunged 10 percent after the short seller released his bearish report on the company Monday morning.
"Citron believes Ubiquiti story is unraveling as we write," Left wrote on his Citron Research website. "The end is now for the Ubiquiti Fraud. What was once a company with unique products in a fragmented space has turned into a company that sells products in highly competitive markets where they are the last mover."
Pera replied to the earlier Citron tweet with his own, saying, "My apologies to those affected by these clowns."
When asked for official comment, Ubiquiti referred CNBC to the CEO's Twitter response. The company will have an investor update featuring Pera on Sept. 26.
Left also questioned the company's use of distributors in the report saying, "Ubiquiti's financials don't reconcile with its distributors." He said Morgan Stanley recently dropped research coverage of the company.
"Like many of the frauds that Citron has uncovered in the past, the cash balances claimed by Ubiquiti do not generate reconcilable interest income," he wrote.
When asked if he is short the stock by CNBC, Left replied in an email, "What do you think?"