San Juan, Puerto Rico ? The father of a Pakistani terrorism suspect at the Guantanamo Bay military prison alleges his son was beaten by U.S. interrogators while held in Pakistan, according to an affidavit released Monday. The CIA denied the prisoner was abused.

Majid Khan, who graduated from a Maryland high school, was deprived of sleep and tied in painful positions during grueling interrogations in the days following his arrest in Karachi, Pakistan, his father, Ali Khan, said in the statement.

The father said he submitted his allegations to undercut the U.S. military’s claims that his son helped al-Qaida mastermind Khalid Sheikh Mohammed plan attacks inside the United States. Mohammed, who admitted planning the Sept. 11 attacks, also is held at Guantanamo.

A spokesman for the Central Intelligence Agency, which held Majid Khan in secret prisons for three years before his transfer to Guantanamo, denied the allegations.

“The United States neither conducts nor condones torture, and the agency acts in strict accord with American law,” spokesman Paul Gimigliano said.

Ali Khan said he learned about the alleged abuse from another of his sons, Mohammed, who was arrested at the family’s apartment in Karachi along with Majid in March 2003 and was briefly detained in the same facility as his brother.

“The Americans tortured him for eight hours at a time, tying him tightly in stressful positions in a small chair until his hands, feet and mind went numb,” Khan wrote in the affidavit submitted to a military review panel that is determining whether Majid Khan can be held as an “enemy combatant.”

Majid Khan arrived at Guantanamo last September with 13 other “high-value” detainees, including Mohammed. U.S. officials allege Mohammed enlisted Khan to blow up service stations and poison reservoirs in the United States.