The abrupt resignation of CIA Director David Petraeus continued to raise questions, especially about the timing of the military hero's admission of an extramarital affair, which came just days after the presidential election and days before he was set to be a critical witness in the controversy surrounding the attack on the U.S. embassy in Benghazi.

"It stinks to high heaven," a senior GOP congressional staffer, who deals with intelligence issues, told The Washington Examiner on Saturday. "Right after the election, right before his testimony on Benghazi -- there's a lot of questions that need to be answered before we're satisfied."

President Obama accepted the resignation of Petraeus, 60, on Friday, and in a letter to staffers, the CIA chief labeled his personal behavior as "unacceptable, both as a husband and as the leader of an organization such as ours." It was later revealed that Paula Broadwell, who along with Washington Post city editor Vernon Loeb, wrote a highly favorable biography of Petraeus, was the woman involved in the affair. Broadwell, a married mother of two, turned 40 Friday.

The FBI discovered the extramarital relationship after it began monitoring Petraeus' emails, concerned that somebody had been accessing his personal account, a law enforcement official confirmed. According to the source, the FBI responded after another women tipped them off to threatening emails from Broadwell. The monitoring led them to discover the affair.

The resignation of the retired four-star Army general is set against a backdrop of CIA controversy. The agency recently acknowledged -- following weeks of contradictory evidence -- that it had provided security for American officials in Benghazi, four of whom, including U.S. ambassador Christopher Stevens, were killed during a Sept. 11 attack on the U.S. Consulate there.

Petraeus was scheduled to testify before lawmakers this week about the episode. House Homeland Security Committee Chairman Peter King, R-N.Y., among others, said Petraeus should still testify. But Acting CIA Director Michael Morell will do so instead.

A congressional aide told The Examiner that the Senate and House Intelligence committees were unaware of the FBI investigation until right before the news broke.

"Leadership should have been told much earlier," the aide said. "We're still trying to get to the bottom of this."

Administration officials said the White House learned of the affair Wednesday. Obama met with Petraeus on Thursday, when the CIA leader offered to resign, they said. Obama accepted the offer on Friday, and the news broke during the middle of a White House press briefing that afternoon.

One White House aide dismissed allegations that Petraeus' exit was politically motivated as "absurd and patently false." "His letter speaks for itself," the official added.

Some said that Petraeus had no choice but to step down, considering the potential breach of security that could arise from a threat of blackmail.

But even some prominent liberal voices greeted the news with skepticism.

"In practice, is there really such low tolerance for spies who have affairs?" Noam Scheiber, of The New Republic, asked on his Twitter account. "I'd be shocked if so."

The exit of Petraeus adds even more turmoil to a White House in transition. Secretary of State Hillary Clinton and Treasury Secretary Timothy Geithner are also expected to leave the administration soon. The future of Attorney General Eric Holder is also in doubt.

But it was the ouster of Petraeus, the 37-year military veteran, which sent shockwaves through Washington. Petraeus was credited with salvaging gains in Iraq and Afghanistan and enjoyed a rare level of bipartisan support that stoked talks of a future run for the White House.