White House spokesman Scott McClellan told reporters Tuesday the Department of Defense is already probing such allegations.
On Tuesday, Congressional Democrats presented draft legislation that would create an independent commission, which they say would serve the national interest.
Some lawmakers have called for closing down the Guantanamo prison, following recent reports by human rights groups of detainee abuse.
President Bush has not ruled out the possibility, but Vice President Dick Cheney said last week there are no plans to shut it down.
Last month, the U.S. military said it found five instances of mishandling of the Koran, the Muslim holy book, at Guantanamo. It said guards were punished in two cases.
Some information for this report provided by AP, AFP, Reuters.
