Donors' families, meanwhile, filed a lawsuit against the school, claiming the director of the university's Willed Body Program had been selling body parts illegally for years with the knowledge of other UCLA officials. UCLA has denied knowing about the sales.
The director, Henry Reid, was arrested along with another man accused of helping to sell the body parts.
UCLA officials admitted Monday that some body parts were sold to companies, but said they were only used for medical research. They promised to revamp the cadaver program.
"These alleged crimes violate the trust of our donors, their families and UCLA," said Dr. Gerald Levey, dean of UCLA's medical school. "We are investigating how our policies failed to detect these employees' illegal activities."
About 175 people donate their bodies each year to the university for use in anatomy classes, officials said. UCLA officials did not say when the body parts were sold or how many there may have been.
Attorneys representing the family members will seek an injunction from a judge Tuesday to stop the cadaver program.
"We both wanted to help the young doctors learn as much as they could and the best way to do that is with bodies," said Shirley Williams, 73, of Thousand Oaks, whose husband's body was donated to UCLA after he died in 2002 from complications of a stroke. She said she has now decided against donating her body to the school.
"I just find it so difficult that someone would put money higher than the use of these bodies for research," she said.
Reid, 54, was arrested Saturday for investigation of grand theft for allegedly selling corpses and body parts for profit. He was released from jail after posting bail and has declined to comment.
Ernest V. Nelson, 46, was arrested for investigation of receiving stolen property. A UCLA statement said Nelson, who also was released on bail, was not a university employee.
Nelson claimed he acted as a middleman for six years, retrieving body parts from the medical school's freezer and selling them to research companies. He said Reid and other UCLA employees knew what he was doing.
"I call one of the most prestigious universities in the world, their director gives me the protocol, I follow that protocol and they charge me with receiving stolen body parts?" Nelson told the Los Angeles Times for Monday's editions.
He added that he collected the body parts by simply walking into the UCLA Medical Center twice a week with a saw and taking them. Over the years, he said, he cut up approximately 800 cadavers and sold parts to as many as 100 clients.
"If I wasn't supposed to be there, why couldn't they tell me that?" Nelson asked.
Louis Marlin, a lawyer for UCLA, denied that the university knew that the donated bodies were being cut up and sold to others. He said Nelson paid for the parts he took with cashier's checks made out to Reid.
One other UCLA employee who is also suspected as having been involved has been placed on leave. That person has been neither identified nor arrested.
Marlin said Nelson himself brought the situation to light when he filed a claim against the university for $241,000 for body parts he said he paid for and was then ordered to return.