The Pentagon is sending investigators to Guantanamo Bay (search) to look into allegations of prisoner abuse described in recently released FBI documents, authorities said Wednesday, as a new batch of FBI memos were released.

The U.S. Southern Command in Miami assigned Army Brig. Gen. John T. Furlow to lead the investigation, which could begin as early as this week. The military maintains that most incidents detailed in the FBI memos occurred in 2002 when the prison was just opening, and that some of the interrogation techniques labeled as "aggressive" are no longer in use.

"It will be fully investigated," Guantanamo's commanding Army Brig. Gen. Jay Hood said Wednesday.

He said the independent military team was necessary to find and interview people who had left the remote outpost and were no longer under his command.

The small team of investigators, including an attorney, will report their findings to the Southern Command's Army Gen. Bantz J. Craddock in February.

Documents published last month show that FBI agents sent to Guantanamo warned the government about abuse and mistreatment when the first prisoners arrived in 2002, more than a year before a scandal over mistreatment at Iraq's Abu Ghraib (search) prison. One letter, written by a senior Justice Department official and obtained by The Associated Press, suggested the Pentagon failed to act on the FBI complaints.

Also last month, the American Civil Liberties Union (search) released e-mails obtained under the Freedom of Information Act in which the FBI accused military interrogators of inserting lit cigarettes in prisoners' ears and shackling them into a fetal positions for up to 24 hours, forcing them to soil themselves.

A new batch of FBI documents released Wednesday by the American Civil Liberties Union explain how the abuse allegations first surfaced.

They show the agency's earlier descriptions of abuses came in response to a specific request dated July 9, 2004 from Steve McCraw, the assistant director of the FBI's Office for Intelligence. The e-mail asked more than 500 agents who had been at Guantanamo to report whether they had observed "aggressive treatment, interrogations or interview techniques" that violated FBI guidelines.

Out of the 478 responses, 26 agents reported observing detainee mistreatment by personnel other than FBI agents. The 26 summaries were reviewed by FBI General Counsel Valerie Caproni, who determined 17 described "approved DOD techniques" and were thus disregarded. As a result, nine reported incidents were tagged for a follow-up.

An FBI spokesman said those cases were referred to the Pentagon for appropriate action.

The ACLU's executive director, Anthony Romero, said in an interview that the agency's decision to narrow its inquiry to nine cases "raises serious questions about the FBI's willingness to investigate abuse at Guantanamo."

"Unfortunately it took the military this long to investigate the abuse and torture that has been documented in Guantanamo," he added. "It certainly took them long enough to recognize that something was seriously wrong in Guantanamo."

Human rights groups have called for an independent investigation into prisoner abuse at the base, where 550 or so detainees from nearly 40 countries are accused of links to Afghanistan's ousted Taliban regime or the Al Qaeda (search) terror network.

The military, they say, cannot be trusted to investigate itself.

"Although more transparency is always welcome, we're way past the point where internal inquiries can be considered sufficient," said Alistair Hodgett, a spokesman for London-based Amnesty International.

The Pentagon has acknowledged 10 cases of abuse since the detention mission began at Guantanamo, including a female interrogator climbing onto a detainee's lap and a detainee whose knees were bruised from being forced to kneel repeatedly.

Additional investigations into abuse and mistreatment at Guantanamo Bay, as well as other aspects of the detention mission, are also pending, Pentagon officials say.