Washington (CNN) Former US attorney Preet Bharara said Sunday that it's likely President Donald Trump's former national security adviser, Michael Flynn, is in discussions with special counsel Robert Mueller about cooperating with his investigation into Russian meddling in last year's election.

"My view is based on how things used to operate in my office and based on how the world works, (which) is that there's a substantial likelihood that they're at least in discussions with regard to cooperating," Bharara said on CNN's "State of the Union."

Asked if the President should be worried about the possibility that Flynn is cooperating with Mueller's team, Bharara said: "It depends on what the President has done and what the President's conversations with Michael Flynn and others have been. But if you've done bad things, then you should be very worried."

On Thursday, Bharara, who was fired by Trump in March and is now a legal analyst for CNN, tweeted about a New York Times report that Flynn's lawyers have told the President's legal team that they can no longer share information , prompting Bharara to speculate that Flynn could be cooperating with Mueller.

If you're dead to rights, flipping on others and cooperating with the prosecution is the only sane and rational move. Also, prosecutors accept cooperation only if you can provide "substantial assistance." Higher up in the food chain. Stay tuned... https://t.co/ZtAxKGx8Wi — Preet Bharara (@PreetBharara) November 24, 2017

Flynn's lawyers' decision to cease informal information-sharing also could be an indication Flynn is preparing to plead guilty in Mueller's investigation, a source familiar with the matter told CNN last week.

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