Daniel Chong, 23, was picked up in a Drug Enforcement Administration raid April 21. After questioning him, agents told him that he would not be charged and to hang tight in the holding cell until they finished the paperwork to release him.
He spent four days forgotten in a cell before agents finally let him out. Chong said he survived by drinking his own urine. He was treated in the hospital for dehydration, kidney failure, cramps and a perforated esophagus. He had lost 15 pounds.
Chong's attorneys filed the claim on Wednesday against the federal agency, saying his treatment constitutes torture under U.S. and international law.
Chong told The Associated Press that he screamed and kicked to door of his 5-by-10-foot cell for hours. Then, as the days dragged on, he realized he was trapped and began to hallucinate.
"I pretty much lost my mind," he told the AP.
Finally after four days, agents opened the door on a fluke and were bewildered to see Chong, covered in his own feces. He said one agent asked: "Where'd you come from?
Law enforcement experts say the incident was one of the worst cases of its kind.
Republican Congressman Duncan Hunter sent a letter to DEA Administrator Michele Leonhart saying the treatment of Chong raises concerns about the agency's handling and monitoring of individuals in custody.
Hunter is demanding a full account of Chong's incarceration, the process currently in place for holding individuals suspected of unlawful activity and the steps that the DEA is taking to address this matter in its entirety.
"The situation involving Chong may in fact be an isolated incident," Hunter wrote. "Regardless, my concern is that this situation could also be a symptom of a bigger problem, with errors in procedure and oversight possibly extending to the division's law enforcement function."
Chong told the AP that his ordeal started after he went to his friend's house on April 20 to get high, part of a national, annual countercultural ritual on that date.
Chong spent the night there, and the next morning, agents stormed into the house. The raid netted 18,000 ecstasy pills, other drugs and weapons. Nine people, including Chong, were taken into custody, according to the DEA.
The Associated Press contributed to this report.