Daniel Chong's attorney, Eugene Iredale, said Tuesday that no one has yet been disciplined for the incident. He added that no criminal charges will be filed.
The 23-year-old engineering student was at a friend's house in April 2012 when a DEA raid netted drugs and weapons. Chong and eight others were taken into custody.
Agents told Chong he would not be charged and had him wait in the cell at DEA offices in San Diego. In an interview with The Associated Press, Chong said that he screamed and kicked the door of his 5-by-10-foot cell for hours. The door did not reopen for four days, when agents found him covered in his own feces.
Chong said he survived by drinking his own urine and tried to write a farewell message to his mother with his own blood. He was treated in the hospital for dehydration, kidney failure, cramps and a perforated esophagus. He had lost 15 pounds.
In May 2012, Chong filed a $20 million lawsuit against the DEA.
Iredale says the Justice Department's inspector general is investigating what caused Chong's near-death experience.
Chong's attorneys say the DEA had no policy on the treatment of detainees at the time. It does now, and that policy includes cameras in cells and daily inspections.
The Associated Press contributed to this report.