A UC San Diego student, who was forgotten by the Drug Enforcement Administration (DEA) in a cell for five days without food, water or any human contact, has filed a $20 million lawsuit against federal drug officials saying he suffered kidney failure.

Daniel Chong's attorney Eugene Iredale has sent a five-page demand notice to the DEA general counsel, the San Diego Union-Tribune reported.

On April 21, the DEA raided Chong's friend's house in University City, Calif., and finding Chong there, detained and threw him in a holding cell.

On Wednesday, Iredale filed the claim stating that his client was subjected to torture after being forgotten in the cell following the raid.

The deprivation of food and water for four and one-half days while the person is handcuffed the entire time constitutes torture under both international and domestic law, the claim said.

The 23-year-old engineering student said that when he was locked up in the cell he was forced to drink his own urine to survive. Five days later on April 25 he was discovered and was rushed to hospital, where he spent five days in recovery.

He was treated for dehydration, possible kidney failure, cramps and a perforated esophagus, ABC News reported. Chong also lost 15 pounds in five days.

In a press conference on Tuesday, Chong said that he yelled and kicked at the cell door for days but no one responded.

I heard them around me, he said. Every door opening around me.

As days passed, he realized he was trapped inside the cell and began hallucinating after two days.

I had to recycle my own urine, Chong said. I had to do what I had to do to survive.

On Wednesday, the DEA issued an apology to the engineering student from the San Diego.

I am deeply troubled by the incident that occurred here last week, acting special agent-in-charge William R. Sherman said in a statement without mentioning Chong by name. 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. I have personally ordered an extensive review of our policies and procedures.