Michael Hayden, director of the CIA, admitted in front of the Congress on Tuesday that the agency used the controversial interrogation technique known as waterboarding on only three occasions and this after the September 11 terrorist attacks.

"Waterboarding has been used on only three detainees," Hayden told the Senate Intelligence Committee.

He specified the number of detainees subjected to the controversial interrogation technique, which is a first, and also named them. The Congress considers interdicting the technique.

The terrorist who have gone through the horrible technique are al Qaeda suspects Khalid Sheikh Mohammed, Abu Zubaydah and Abd al-Rahim al-Nashiri, Hayden said.

However, it is highly improbable that the CIA used waterboarding only three times. Hayden stated that this technique hasn’t been used in five years and the only reason which determined the CIA to use it again were the fears of imminent disastrous attacks on the United States and because authorities had limited knowledge of al Qaeda.

"The circumstances are different than they were in late 2001, early 2002," Hayden added.

During his statement he also said that he is against limiting the Centre Intelligence Agency to using interrogation techniques permitted in the U.S. Army Field Manual, which bans waterboarding. According to Hayden, CIA interrogators are much better and the agency works with a narrower range of suspects in its interrogations.

Waterboarding is a form of torture that mainly consists of immobilizing a person on his or her back, with the head inclined downward, and pouring water over the face and into the breathing passages.

Through forced suffocation and inhalation of water, the subject experiences the process of drowning in a controlled environment and is made to believe that death is imminent

If performed by “professionals”, the controversial interrogation technique can be performed in ways that leave no lasting physical damage and inflict terrible pain, but it can also cause damage to the lungs, brain damage caused by oxygen deprivation, injuries due to struggling against restraints, and even death.