(CNN) -- A chemist accused of failing to follow protocols at a Massachusetts crime lab had been involved in testing some 50,000 drug samples, potentially opening the door to a swath of legal challenges, officials said Wednesday.

The list of samples was turned over to prosecutors and public defenders on Tuesday. The samples were tested during Annie Dookhan's nine-year term at the facility, state authorities said. The samples were from an estimated 34,000 cases Dookhan worked on during her career, authorities said.



"Fifty-thousand drug samples in question could mean numerous wrongful convictions, vacated sentences, dismissed cases, overturned convictions and so on," said Anne Goldbach, forensic services director Committee for Public Counsel Services. "Whether or not all those samples were affected, we don't know."

Goldbach said investigators first learned of a breach in protocol in February over a June 2011 incident in which samples were incorrectly catalogued.

"This is going to be a huge amount of work for both defense and prosecution attorneys and a huge drain in resources in attempting to figure out the extent of the situation," Goldbach said.

The Boston lab certified drug samples for Massachusetts law enforcement before Gov. Deval Patrick ordered it closed August 30 in the wake of an investigation into the scandal.

"This is deeply troubling information," Patrick said in statement last week. "No breach this serious can or will be tolerated. The State Police will continue their investigation to determine what happened and who is responsible so that we can hold those accountable."

The state's Department of Public Health said it had "placed an additional lab supervisor on leave pending the outcome of our investigation."

"Our job now is to continue to work with the Attorney General's Office to get to the bottom of what went wrong, assign accountability where it is warranted and prevent this type of breach from happening again."

Dookhan could not be immediately reached comment.