WASHINGTON - A rash of US government scandals have prompted a flurry of unanswered questions over what White House officials knew and when they knew it.

Last week saw a firestorm of controversy after the Internal Revenue Service (IRS) admitted to inappropriately - and possibly illegally - targeting conservative political groups such as the Tea Party during the 2012 election cycle in a scandal that has drawn criticism from both Republicans and Democrats.

In an admission that Obama administration officials knew of the issue during the lead up to the elections, the Treasury Department ' s inspector general told a Congressional hearing Friday he informed senior Treasury officials in June 2012 that he was investigating charges that the IRS had targeted conservative groups.

J. Russell George said he told Treasury's general council on June 4, as well as Deputy Treasury Secretary Neal Wolin a short time after that.

That admission prompted further questions over whether Wolin had informed his boss at the time, former Treasury Secretary Timothy Geithner, and whether the scandal had been kept under wraps because it emerged during an election year.

It also remains unclear whether the alleged targeting was an effort to streamline productivity - IRS workers were told to target organizations with "Tea Party" and "Patriot" in their names - or whether the move was politically motivated.

Also unclear is who created the criteria to single out conservative groups.

On Wednesday, key IRS official Lois Lerner refused to testify in a hearing on the scandal, citing her First Amendment rights, which preclude individuals from being forced to testify against themselves in a criminal case.

President Barack Obama expressed outrage last week over the controversy and vowed to get to the bottom of the ordeal, pledging to work with Congress as its investigation unfolds.

Meanwhile, journalists and lawmakers continue to express outrage over the Justice Department's secretly obtaining two months of phone records from the Associated Press, including its reporters' home phones and cell phones.

Critics question why the justice department did not give the AP advanced notice of the seizure, which is the usual protocol.

Republicans continue to push for more information on the administration's handling of last September's terrorist attack on the US consulate in Benghazi, Libya, which ended in the deaths of four Americans, including Ambassador Christopher Stevens.

While the White House has called the push a partisan "side show, " Republicans maintain there are holes in the story, and are calling for former Secretary of State Hillary Clinton to appear again before a Congressional hearing.

Earlier this month, Gregory Hicks, the second-ranking American diplomat in Libya during the assault by terrorists, told a Congressional hearing he was "stunned" and "embarrassed" when,in the days following the attack, UN Ambassador Susan Rice wrongly said the assault stemmed from a spontaneous demonstration sparked by an anti-Muslim video, when in fact it had been a planned attack.

Some critics charged the White House with attempting to avoid embarrassment in the lead-up to the 2012 presidential elections in a bid to continue its narrative that terrorism was on the wane after US forces killed Osama bin Laden in 2011.

Critics are calling for the administration to release the name of the individual who told Rice to provide the talking points.

Republican Strategist Ford O'Connell told Xinhua that the IRS scandal is the most damaging to the White House of all the controversies, as many Americans are distrustful of the powerful agency that has the power to tax, levy financial penalties and prosecute individuals for allegedly breaking tax laws.