This article was produced in partnership with the Pulitzer Center on Crisis Reporting.

GUANTÁNAMO BAY, Cuba — After a few weeks of waterboarding the captive in August 2002, the C.I.A. contract psychologists who had developed the interrogation program wanted to stop. The prisoner, a Palestinian known as Abu Zubaydah, was cooperating, and there did not seem to be any point in continuing to torture him.

But senior intelligence officials wanted them to press on, one of the psychologists, James E. Mitchell, testified to the military tribunal at Guantánamo on Wednesday.

“Please continue with the aggressive interrogation strategy for the next 2-3 weeks,” their C.I.A. supervisors cabled them, even after the psychologists had sought permission several times to stop using the waterboard and had sent their bosses a disturbingly graphic video montage of what they had been doing.

Dr. Mitchell said those directing the operation derided the psychologists as “pussies” and believed that, contrary to reports from the secret C.I.A. prison in Thailand where they were carrying out the interrogation, Mr. Zubaydah could yield some information about what they feared were looming terrorist attacks. If they would not continue, their supervisors threatened to replace them with someone more aggressive.