The National Police Agency said Thursday it will re-examine 199 drunken driving cases due to concerns that faulty breathalyzers may have been used as a basis for convictions.
The NPA announced the move following revelations that a new type of breathalyzer introduced late last year by some prefectural police forces malfunctions when used in cold air. The devices suspected of malfunctioning were used in eight of the 199 cases, which took place in Fukuoka, Yamagata, Shiga, Wakayama and Kumamoto prefectures.
The other 191 cases involved the use of its predecessor model, the reliability of which must be verified in light of the malfunctions of the new version, according to the NPA.
The NPA suspended the use of both models in November, and said it has set up a team to investigate their reliability.
Prosecutors earlier said they plan to take the unusual step of demanding retrials in some cases that resulted in convictions.
Criminal procedures on six questionable cases have been suspended, the NPA said.
But NPA officials also claimed unjustified convictions are highly unlikely because police do not test people without signs of drunkenness, such as a person's breath smelling of alcohol.