SAN FRANCISCO -- Twenty drug suspects were set free Wednesday instead of being arraigned on narcotics charges in court in the wake of a scandal involving a former technician allegedly sampling cocaine in the San Francisco Police Department’s Crime Lab, prosecutors said.

SF District Attorney’s Department spokesman Brian Buckelew said it was unclear just how many cases the alleged actions by 60-year-old Debbie Madden would ultimately impact. But until an extensive audit is completely by the police, Buckelew said, the process of charging drug suspects would be halted.

“When these revelations first came to light the District Attorney’s Office wanted to foster two goals,” the assistant DA told KTVU. “The first goal is to ensure the integrity of the narcotics testing in the San Francisco Police Department Crime Lab. The second goal is to ensure the public that people who committed felony offenses will be held responsible.”

But with questions now surrounding the lab, Buckelew said, the suspects scheduled to appear in court on Wednesday will be freed instead of being charged.

“What is happening today is that the narcotics cases that were set for arraignment will be discharged,” he said. “The narcotics (evidence in those cases) will be sent out a separate lab for testing. That doesn’t mean the cases are dismissed. It means that the cases will be charged at a future date once the narcotic results come from a separate lab.”

Buckelew said the police department was set to begin an intensive audit of the lab on Wednesday.

“We really don’t know the extent of the problem yet,” said Buckelew adding that suspects to be arraigned on Thursday would also likely be released.

The initial audit done by the police, the assistant DA said, has revealed at least six ‘irregularities’ in cases involving Madden who resigned from the crime lab.

The revelation of her alleged actions was made public Tuesday night at a hastily called press conference. Authorities said Madden allegedly sampled cocaine seized in cases to feed an addiction to the drug.

The narcotics section of the police department's crime lab was immediately shut down and the agency asked nearby agencies for help.

But the evidence collected in hundreds of drug cases was thrown into question.

"One of our supervisors noticed in late December that some of the packaging had been tampered and then we also had information that maybe she had been taking evidence," said San Francisco Police Chief George Gascon at the press conference.

Sources said Madden was one of two criminalists employed at the lab responsible for analyzing evidence for up to 50 cases a day.

She had been with the department, testing drugs and testifying in cases for 29 years. But that ended last week when Madden suddenly retired on March 1st.

Two days later, San Mateo County Sheriff's executed a search warrant at her home. She was arrested for firearms possession in violation of a domestic violence case.

Sources told KTVU a small amount of cocaine was also found in her home.

"It's disappointing and it puts the hard work of everyone else in the crime lab into question," said Chief Gascon.

The police chief insisted the theft was isolated to just the one employee. District Attorney Kamala Harris believed past drug convictions will hold despite these allegations.

"By no interpretation should anyone think that re-testing these drugs will in any way give anybody who was involved in a drug crime in the city a get out of jail free card," said Harris.

The crime lab is in the process of being re-accredited. A draft report recently completed suggests several areas for improvement.

On Tuesday night, the chief said he will act upon those recommendations. In the meantime, officials expected Madden to face charges in San Francisco.