Some alcohol breath tests for drivers recently charged with DWI in Middlesex County were inaccurate, according to Middlesex District Attorney Marian Ryan.

Ryan said the problem could be more widespread and said the tests will not be used until further notice.

"In mid-March we were notified by the Office of Alcohol Testing that there was an issue with breath tests given to several identified defendants in Middlesex County," Ryan said in a statement. "We have notified defense attorneys in those active cases and we are in the process of contacting attorneys in identified disposed cases.