DPS officials said they suspended the supervisor's certification, and the Texas Rangers launched a criminal investigation.
"These are serious allegations and we will not tolerate any activities that call into question the integrity of the breath test system," said Col. Stan Clark, interim DPS director.
Police use breath analyzers to determine whether someone is legally intoxicated.
The DPS Forensic Breath Alcohol Laboratory regulates the state's breath alcohol testing program. The technical supervisors -- those who work for DPS and those hired by police agencies -- are required to inspect each breath test instrument at least once a month.
DPS officials say the contractor had been faking records up to a year and that at least 2,600 DWI cases could be affected.
The breath test devices were used by the Clute, Friendswood, Galveston, League City, Pearland, Seabrook, South Houston and Webster police departments.
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