Washington (CNN) A top Senate Democrat defended David Petraeus on Sunday, saying the Justice Department erred in recommending charges against the former top Army general and Central Intelligence Agency director.

"This man has suffered enough in my view," Sen. Dianne Feinstein of California, the former Senate Intelligence Committee chairwoman, told Gloria Borger, CNN chief political analyst on CNN's "State of the Union."

Her comments come after news that the Justice Department is recommending charges against Petraeus, first reported by The New York Times

Feinstein called Petraeus, who led U.S. efforts in Iraq and Afghanistan under President George W. Bush and later President Barack Obama, "the four-star general of our generation" and "a very brilliant man."

She said Petraeus' affair with Paula Broadwell, his biographer, and his allowing her access to some classified government documents while she was with him was a mistake -- but not one for which he should face criminal charges.

"It's done, it's over. He's retired. He's lost his job," Feinstein said. "I mean, how much does government want?"

Her comments came on the heels of similar criticism by Republican Sens. John McCain of Arizona and Lindsey Graham of South Carolina, who called the investigation "grievously mishandled."

"It is outrageous that the highly confidential and law enforcement-sensitive recommendation of prosecutors to bring charges against Gen. Petraeus was leaked to The New York Times. It is a shameful continuation of a pattern in which leaks by unnamed sources have marred this investigation in contravention to fundamental fairness," the two said in a statement issued Saturday.

"No American deserves such callous treatment, let alone one of America's finest military leaders whose selfless service and sacrifice have inspired young Americans in uniform and likely saved many of their lives," they said.

In a Sunday appearance on CNN's "State of the Union," McCain said Petraeus is "a genuine American hero" and that his rights are being violated by the leak of information on the investigation.

McCain said he's not sure whether Petraeus should be charged because he doesn't know what the Justice Department has found -- though classified information is leaked to journalists every day in Washington. Instead, McCain said his issue was with the handling of the case.

"This man is unique," McCain said. "He is one of the great leaders."

Neither the Justice Department nor an attorney for Petraeus commented on Saturday and Attorney General Eric Holder deflected a question on the department's handling of the Petraeus investigation.

"I don't want to comment on what is an ongoing matter," Holder said on CNN's "State of the Union."

"I will say that frequently, those things that are leaked to the media are done so by people who are not in the position to know, and are frequently inaccurate," he said.