A North Hollywood doctor charged Tuesday with conspiring to illegally distribute painkillers is being investigated regarding the role his prescriptions may have played in the deaths of six patients from Ventura County, according to a prosecutor.

Dr. Bernard Bass, a 61-year-old pain management specialist who sees patients from Los Angeles and Ventura counties, was charged with writing 406 prescriptions in the past two months without a license. Bass surrendered his license to prescribe to the U.S. Drug Enforcement Administration in May after Ventura County sheriff's detectives searched his office and home, seizing about $1.7 million of cash and assets.

An arraignment and hearing on bail — set preliminarily at $1 million — was scheduled for Tuesday but was pushed back to today. Bass' lawyer, Michael David Nasatir, declined comment on the charges or the ongoing investigation.

"We're going to make our legal arguments in court," he said.

Bass, arrested Thursday at his home in Burbank, also is being investigated for potential homicide charges related to the alleged overdose deaths of several patients, according to a court document filed by the sheriff's department.

Senior Deputy District Attorney Ryan Wright said the investigation centers on the deaths of six people from Ventura County since 2005. He said four of the deaths happened this year.

"The ongoing investigation consists of whether there's a link between these prescription practices and the deaths," said Wright, adding prosecutors are still awaiting evidence, including findings of specific causes of death in some of the cases.

The charges filed Tuesday don't deal with the deaths but allege that Bass not only prescribed without a license but also backdated his prescriptions. Prosecutors said Bass provided such prescriptions to 19 patients from Ventura County after surrendering his license. They also allege he told a pharmacy in North Hollywood his license had been restored.

The charges accuse Bass of being a conspirator in the crimes but say that his partners are unknown.

In the court document from the Sheriff's Department, Detective Victor Fazio said Bass would charge $80 in cash and write all of his patients the same prescription, usually without any physical examination.

Fazio argued the $1 million bail was needed to keep Bass from continuing to prescribe medication.

Bass' lawyers filed documents Tuesday with Superior Court Judge Kevin McGee in response to the bail. Though not immediately available, the documents included character references and other arguments asserting Bass does not present a safety risk, Wright said.

Bass has entered into an agreement with the California Board of Medicine to stop practicing medicine until the legal proceedings are completed, said Esther Kim, a state deputy attorney general.

The Medical Board filed its own case against Bass in May regarding seven patients, including one who died. The board accused Bass of gross negligence, violating drug-prescribing laws, failure to maintain records and excessive prescribing. A hearing in the case has not been scheduled.