LITTLE FALLS - A state police lab technician who was suspended for allegedly faking test results in drug cases is now facing a criminal investigation.

The public defender's office says that Kamal Shah mishandled data collected in one case about marijuana he was supposed to be testing.  Shah worked for the New Jersey State Police Crime Lab for 10 years.

Shah was suspended without pay in December when the allegations came to light. A criminal investigation was announced Thursday.

Former Middlsex County Prosecutor Tom Buck says that the revelation of Shah’s alleged actions has thrown thousands of lab test results into question.

"Any convictions that Mr. Shah had anything to do with puts those convictions absolutely in doubt,” Buck says.

Prosecutors have retested drugs from some open cases, but it's not clear how possible that will be on many closed cases that Shah worked on.

Attorney Emile Lisboa told News 12 New Jersey last month that he has been going through his cases and found that six of his clients may be affected.

"I have two clients who've served jail sentences. I don't know how you get that time back,” Lisboa said.

Many of the samples cannot be retested because the evidence has already been destroyed. Many defense attorneys have already filed motions to have convictions thrown out and guilty pleas withdrawn.

The attorney general's office instructed all county prosecutors to contact defense attorneys in trials where Shah-prepared lab reports were used to convict drug defendants.