"There is absolutely evidence to begin a case" for obstruction of justice by Trump, Bharara said in his first television interview since being fired by Trump in March.
"No one knows right now whether there is a provable case of obstruction," Bharara added. "[But] there's no basis to say there's no obstruction."
Bharara was U.S. attorney for the Southern District of New York until March when he and 45 other U.S. attorneys remaining as holdovers from the Obama administration were told to step down.
The action came after Trump had previously asked Bharara to stay on as U.S. attorney, according to Bharara and those close to him. “I did not resign. Moments ago I was fired,” Bharara announced in a tweet on March 11.
Bharara told Stephanopoulos that watching how James Comey's interactions with Trump and how his firing played out "felt a little bit like déjà vu."
Bharara said Trump, starting when he was still president-elect, made a series of "unusual phone calls" to him.
"In reporting the phone call to the chief of staff to the attorney general I said, it appeared to be that he was trying to cultivate some kind of relationship," Bharara said. "It's a very weird and peculiar thing for a one-on-one conversation without the attorney general, without warning between the president and me or any United States attorney who has been asked to investigate various things and is in a position hypothetically to investigate business interests and associates of the president."
After Trump took office, Bharara refused to take one of Trump's calls.
"The call came in. I got a message. We deliberated over it, thought it was inappropriate to return the call. And 22 hours later I was asked to resign along with 45 other people," Bharara said.
"To this day I have no idea why I was fired," Bharara added later.