Facebook CEO Mark Zuckerberg has done a "horrible, horrible" job handling the social media giant's latest crisis, technology investor Jason Calacanis told CNBC on Monday.
He said it's time for COO Sheryl Sandberg to step into the role.
Facebook has come under fire after reports that conservative research firm Cambridge Analytica gained access to data from 50 million Facebook profiles before the 2016 presidential election.
Calacanis, CEO of Inside.com and an early investor in Uber, said Zuckerberg has been "MIA."
"It's a complete and utter failure of leadership," he said on "Closing Bell."
Sandberg is a "better communicator" and a "tremendous leader," Calacanis said.
"She's better at understanding how to manage these issues," he said.
On Monday, Facebook said it has hired a firm to conduct a "comprehensive audit" of Cambridge Analytica and the whistleblower, Christopher Wylie, who set off the firestorm. It suspended Cambridge Analytica from the site late Friday night.
Meanwhile, Cambridge Analytica has denied violating Facebook's terms of service and said Wylie is misrepresenting himself and the company.
Facebook closed down almost 7 percent on Monday, dragging tech stocks down with it.
Calacanis said the company has moved from an existential crisis to an actual crisis, calling it a "big deal."
While he doesn't foresee any user backlash right now, he said, there are other issues at stake, such as the ability to buy companies and to attract top talent.
Facebook did not immediately respond to a request for comment on Calacanis' remarks.
— CNBC's Sara Salinas contributed to this report.