Lawyers for convicted drug offenders and the state of Massachusetts are wrangling in court this week over the allegedly botched handling of evidence in the investigation of criminal-lab technician Sonja Farak — in hearings that could help decide how many of thousands of convictions may be overturned because of her tainted testing.

As The Eye reported in May, emails among prosecutors and police show the state had evidence that Farak was sampling evidence in the lab to feed her addiction for a longer time than revealed at the time of her 2013 arrest and trial. At the time, lawyers for defendants facing charges that rested on her lab tests were rebuffed by the state in their efforts to see files that later were shown to contain evidence of her earlier use.

Now, 11 of those defendants are seeking a ruling that misconduct in the state attorney general’s office was the reason the evidence was withheld. A ruling that the Commonwealth withheld this information, and particularly that prosecutors did so deliberately, would lend support to calls from the defense bar to dismiss an estimated 18,000 cases she touched. In hearings this week in Springfield before Superior Court Judge Richard Carey, lawyers for the state and the defendants both lobbed critical questions at former assistant attorney general Kris Foster, who took the stand Tuesday.

Foster was responsible for handling requests from drug defendants for evidence gathered in the Farak investigation. Foster, who is now general counsel at the Massachusetts Alcoholic Beverages Control Commission, testified she never personally examined any of the key documents taken form Farak’s car that showed her earlier use, and that she was following instructions from her supervisors.

Both sides assailed Foster for allegedly making representations to the court at the time about what was in the files without reviewing the evidence, even after a judge told her to review it. “Did you think it might be a good idea given the representations you made to the court, a personal letter to a Superior Court judge, that you might want to do that kind of investigation to see what had been turned over?” asked defense attorney Luke Ryan. Kim West, head of the attorney general’s Criminal Bureau, was more blunt. “Do you agree that some of your actions in this case might have constituted poor practice, but were never deliberately made in order to conceal records?” asked West.

Foster disputed the “poor practice” characterization, but said that she would review the evidence files herself if given the chance to do so today. She said she did what superiors directed her to do and believed in good faith that all documents had been provided to defendants.

Judge Carey will hear testimony this week from Foster’s supervisors in the attorney general’s office, as well as from Farak’s coworkers at the Amherst drug lab and Anne Kaczmarek, who led the prosecution of Farak. The hearings come a month after the Massachusetts Supreme Judicial Court heard arguments in cases arising from the Annie Dookhan drug lab scandal. The defendants’ attorneys argued that Dookhan’s misconduct — certifying samples as narcotics without conducting any testing and falsifying her credentials — similarly demands dismissal of all approximately 24,000 “Dookhan defendant” cases because there simply are not enough public defenders to handle them all.