Federal prosecutors say troopers from a Massachussetts State Police unit had a quota system for issuing tickets to motorists, a practice that state courts have deemed unconstitutional and agency officials have repeatedly denied exists.

Members of the now-disbanded Troop E were expected to issue at least eight citations during their shifts under a specialized overtime program, which dozens of troopers allegedly abused to collect fraudulent overtime, according to prosecutors.

“Any failure to issue the required number of citations had to be explained to supervisors and command staff,” prosecutors wrote in a new court filing included in the ongoing overtime case. “Repeated failures to meet this quota often resulted in a trooper being blocked from receiving such overtime opportunities.”

The allegation emerged last week in a sentencing memo for former trooper Eric Chin, who pleaded guilty late last year to embezzlement as part of the federal investigation into overtime abuses at the agency, the Boston Globe reports.