Update: The Drug Enforcement Administration has apologized to Danny Chong after he spent five days in a holding cell without food, water or a toilet, the LA Times reported.

"I extend my deepest apologies [to] the young man and want to express that this event is not indicative of the high standards that I hold my employees to," William Sherman, special agent in charge of the San Diego division of the DEA, said in a statement. He added that he has ordered "an extensive review" of DEA procedures.

Earlier:

An innocent California student was placed in a holding cell after his buddy's house was raided by the Drug Enforcement Administration, and ended up spending nearly five days in his dark prison without food, water or human contact.

Danny Chong, 24, had been told that he was going to be released on April 20 -- the same day he was detained -- because he wasn't charged with any crime.

Officers reportedly forgot about him. He told NBC that he was forced to drink his own urine for hydration and ended up carving his own flesh with glass in a fit of psychosis.

"I had to do what I had to do to survive," he told the station on Tuesday. "I was completely insane."

Chong's horrific -- and accidental -- stay in the dark holding cell began on April 20, when agents raided a home that Chong where hanging out near UC San Diego. DEA officials said they found some 18,000 ecstasy pills at the home, but that Chong wasn't involved. He was brought in for questioning, but never formally arrested or charged, according to U-T San Diego.

He was supposed to leave his detention the same day. One officer even offered him a ride home.

But he was forgotten inside his 5-foot-by-10-foot, windowless enclosure.

He kicked, screamed and cried as the days passed. He could hear DEA agents on the other side of his heavy door, but they apparently couldn't hear him. He didn't have food, water or a bathroom.

At one point Chong went so "insane" he broke his glasses with his teeth and carved "Sorry Mom" into his arm.

By day five -- when corrections officers finally heard Chong's screams for help -- he'd been hallucinating and even attempted to eat broken glass, NBC reported.

When agents finally found Chong, he was incoherent and had to be taken to the hospital, according to the Associated Press. He was treated for a perforated lung -- an injury consistent with someone who has eaten glass.

The student's lawyer compared his detention to the famous Abu Ghraib prison in Iraq. Chong is considering filing a civil lawsuit against the DEA.

The DEA maintains that the incident was accidental and isolated, but hasn't elaborated.