WASHINGTON - A former CIA officer who participated in the capture and questioning of the first al-Qaeda terrorist suspect to be waterboarded said yesterday that the harsh technique provided an intelligence breakthrough that "probably saved lives" but that he now regarded the tactic as torture.

Abu Zubaydah, the first high-ranking al-Qaeda member captured after the Sept. 11 attacks, broke in less than a minute after he was subjected to the technique and began providing interrogators with information that led to the disruption of several planned attacks, said John Kiriakou, who served as a CIA interrogator in Pakistan.

Abu Zubaydah was one of two detainees whose interrogation was captured in video recordings that the CIA later destroyed. The recent disclosure of the tapes' destruction ignited a furor on Capitol Hill and prompted allegations that the agency had tried to hide evidence of illegal torture.

"It was like flipping a switch," said Kiriakou, the first former CIA employee directly involved in the questioning of "high-value" al-Qaeda detainees to speak publicly.

In an interview, Kiriakou said he had not witnessed Abu Zubaydah's waterboarding but was part of the interrogation team that had questioned him in a Pakistan hospital for weeks after his capture in that country in the spring of 2002.

He described Abu Zubaydah as ideologically zealous, defiant and uncooperative - until the midsummer day when his captors strapped him to a board, wrapped his nose and mouth in cellophane, and forced water into his throat in a technique that simulates drowning.

The waterboarding lasted about 35 seconds before Abu Zubaydah broke down, according to Kiriakou, who said he was given a detailed description of the incident by fellow team members. The next day, Abu Zubaydah told his captors he would tell them whatever they wanted, Kiriakou said.

"He said that Allah had come to him in his cell and told him to cooperate, because it would make things easier for his brothers," Kiriakou said.

Kiriakou's remarks came a day before top CIA officials were to appear before a closed congressional hearing to account for the decision to destroy recordings of the interrogations of Abu Zubaydah and another senior captive, Abd al-Rahim al-Nashiri. On Thursday, CIA Director Michael V. Hayden announced that the recordings had been destroyed in 2005 to protect the identities of CIA employees who appeared on them.

The recordings were destroyed despite orders from judges that required the government to preserve records related to its interrogation programs. The lawsuits were filed by captives at the Guantanamo Bay military prison who were contesting their detentions.

Also yesterday, the chairman of the House intelligence committee, Silvestre Reyes (D., Texas), and ranking Republican, Peter Hoekstra of Michigan, announced that the panel would launch its own investigation into the tapes' destruction. They said in a statement that Hayden's assertion that the committee had been "properly notified" of the destruction "does not appear to be true."

The Justice Department and the CIA inspector general's office also have begun a preliminary inquiry. Members of the bipartisan commission that investigated the Sept. 11 attacks have said they repeatedly were told that the CIA did not have videotapes of interrogations.

Agency officials have said they briefed intelligence committee leaders from both parties on interrogation techniques over the course of two years. Officials said that the briefings included mention of the tapes but that none of the lawmakers asked to view them.

U.S. intelligence officials confirmed that Kiriakou was a CIA employee involved in the capture and questioning of Abu Zubaydah. Kiriakou, a 14-year veteran of the CIA who worked in both the analysis and operations divisions, left the agency in 2004 and works as a consultant for a private Washington-based firm.

After the hospital interviews bore no fruit, Abu Zubaydah was flown to a secret CIA prison, where the interrogation duties fell to a team trained in aggressive tactics, including waterboarding. Shortly before the transfer, Kiriakou said he left Pakistan for Washington, where he said he continued to monitor the interrogation through classified cables and private communications with colleagues.

Kiriakou said he did not know that the interrogations were videotaped, although there often were closed-circuit video systems in the rooms where questioning took place. He said he also had no knowledge of the decision to destroy videotapes of the interrogations.

Officials said that there were hundreds of hours of recordings but that most were of Abu Zubaydah alone in his cell, recovering from his injuries.

The circumstances surrounding Abu Zubaydah's interrogation and treatment are still murky and fiercely disputed. FBI agents have opposed the use of coercive techniques as counterproductive and unreliable; intelligence officials have defended the tactics as valuable.

President Bush and others have portrayed Abu Zubaydah as a crucial and highly placed terrorist. Some intelligence and law-enforcement sources have said he did little more than help with logistics for al-Qaeda leaders and their associates.