The reaction of the fraternity's national office requires no further comment.
A five-month investigation prompted by a cocaine overdose death last year led to the arrests of 96 people, 75 of them San Diego State students. A second drug death occurred while the investigation went on.
Twenty-nine people were arrested early Tuesday in raids at nine locations including the Theta Chi fraternity, where agents found cocaine, Ecstasy and three guns. Eighteen of them were wanted on warrants for selling to undercover agents.
Two kilograms of cocaine were seized in all, along with 350 Ecstasy pills, marijuana, psychedelic mushrooms, hash oil, methamphetamine, illicit prescription drugs, several guns and at least $60,000 in cash, authorities said.
Profits may have been used to finance fraternity operations, they said. Those arrested included a student who was about to receive a criminal justice degree and another who was to receive a master's degree in homeland security.
"A sad commentary is that when one of these individuals was arrested, they inquired as (to) whether or not his arrest and incarceration would have an effect on him becoming a federal law enforcement officer," said Ralph Partridge, special agent in charge of the U.S. Drug Enforcement Administration in San Diego.
During the probe, investigators discovered that in some fraternities most members were aware of "organized drug dealing occurring from the fraternity houses by its members," the DEA said in a news release.
Theta Chi, based in Indianapolis, has 131 chapters in the U.S. and Canada and more than 161,000 initiates. It was founded in 1856.
The San Diego chapter was founded 61 years ago and has 65 members.
"They were on the upswing," [national executive director Dale] Taylor said. "They had improved their recruitment. They were trying to raise money for a new house."