LOS ANGELES — Unnecessary surgeries performed by untrained assistants are among the allegations in an indictment detailing a $150 million insurance scheme, among California’s biggest ever.

Orthopedic surgeon and alleged ringleader Dr. Munir Uwaydah and 14 associates, including another doctor and a lawyer were named in the indictment unsealed Tuesday, Los Angeles District Attorney Jackie Lacey said.

Nearly two dozen patients were told Uwaydah would perform surgery on them, only to have his physician’s assistant — who had not attended medical school — operate once they were under anesthesia, according to the indictment. Uwaydah wasn’t even present for the surgeries.

“All 21 patients sustained lasting scars and many required additional surgeries and suffered physical and psychological trauma as a result of their experience in Uwaydah’s clinics,” prosecutors said in a news release.

Uwaydah, 49, was arrested in Germany on the 57-count indictment and awaits extradition.

Eleven co-defendants appeared briefly in Los Angeles Superior Court and had not guilty pleas entered on their behalf. They were held on bail as high as $21.5 million.

The case has a subplot involving Uwaydah’s office assistant, who was acquitted two years ago of strangling the doctor’s ex-girlfriend, an aspiring model and actress.

Prosecutors had described Kelly Soo Park as a “female James Bond” who was hired to kill Juliana Redding because of a failed business deal between her father, who is an Arizona pharmacist, and Uwaydah. The doctor was never charged in the case and denied any involvement in the killing.

Park, who was in tears when she was acquitted of murder, wept as she appeared for her arraignment in the fraud scheme. She was held on $18.5 million bail.

The attorney who represented Park in the murder case stood by her again Tuesday. He said he was suspicious of retribution from prosecutors bringing the case against her.

“In the previous case some of this was in the air,” attorney George Buehler said outside court. “The DA wanted to bring that in. It wasn’t admitted. I think they’ll have a terribly hard time of tying her into fraud in this case.”

In another development, the prosecutor who presented the Redding killing case to the grand jury is now a defense lawyer and representing another defendant in the fraud scheme.

Deputy District Attorney Dayan Mathai said he will seek to have attorney Alan Jackson, who went into private practice after losing the race for district attorney, removed from the case because of a conflict of interest. Jackson refused to comment.

The case, which includes allegations spanning more than a decade, involves a conspiracy to pay attorneys and marketers up to $10,000 a month to illegally refer patients, including those with workers’ compensation claims, to the doctor and his related businesses.

In one indictment, Uwaydah, Park and nine others are charged with a single conspiracy count, 32 counts of insurance fraud, three counts of illegal client referrals and 18 counts of aggravated mayhem, which involve disabling or disfiguring someone. Uwaydah and the physician’s assistant, Peter Nelson, were also charged with three additional aggravated mayhem counts.

In a related 75-count indictment, Uwaydah’s lawyer and three others were charged with conspiracy to commit insurance fraud, money laundering, illegal patient referrals and filing false tax returns.

Uwaydah and the 11 defendants in the first indictment face up to life in prison if convicted.