WASHINGTON, (Reuters) – Waterboarding and other  harsh interrogation methods used during the Bush administration  on terrorism suspects produced unreliable evidence and were  ineffective, a former FBI agent told Congress yesterday.

Ali Soufan made the charge before a Senate Judiciary panel  in the first congressional hearing since the release last month  of Justice Department memos that authorized tactics such as  waterboarding, sleep and food deprivation and forced nudity.

“These techniques … are ineffective, slow and unreliable  and as a result harmful to our efforts to defeat al Qaeda,”  said Soufan, who noted that he obtained valuable intelligence  from al Qaeda suspects without using harsh methods.

He said he objected to the practices of CIA interrogators.

“I could not stand by quietly while our country’s safety  was endangered and our moral standing damaged,” he said.

The hearing occurred amid increasing calls by human rights  groups for more investigation and perhaps even criminal  prosecutions of Bush administration officials for the  techniques denounced by critics as illegal torture.

Soufan also interrogated prisoners at Guantanamo and was a  key prosecution witness last year during the only two trials  completed in the special tribunals at the U.S. Navy base in  Cuba. His testimony helped convict Osama bin Laden’s driver,  Salim Hamdan, and al Qaeda videographer Ali Hamza al Bahlul.

Soufan, born in Lebanon, was one of a handful of native  Arabic speakers at the FBI before the Sept. 11 attacks and was  one of the bureau’s top experts on al Qaeda.

During the hearing, a Democratic senator said former Vice  President Dick Cheney had been misleading the American people  by saying the harsh interrogation methods had produced valuable  intelligence.

“Nothing I have seen, including the two documents to which  … Cheney has repeatedly referred, indicates that the torture  techniques authorized by the last administration were necessary  or that they were the best way to get information out of  detainees,” Senator Russ Feingold said.

President Barack Obama also has questioned Cheney’s  description of the information contained in the classified  documents. In one of his first acts as president, Obama ordered  more humane treatment for terrorism suspects.