An Auckland police officer has beaten a drink driving charge by using a little known legal loophole.



Detective Constable Wayne Dennis Mead, 34, from Counties Manukau CIB was stopped in central Auckland on February 17 and gave a breath alcohol reading of 619mcg per litre of breath. The limit is 400mcg.



He was acquitted in the Auckland District Court last month on the grounds he was not given an uninterrupted 10 minutes to decide if he wanted a blood test, the Herald on Sunday reported.



During the 10 minute period Mr Mead was supposed to be granted to think about the situation, he asked and was allowed to call his boss.



Judge Graham Hubble ruled that the uninterrupted break had not been established and dismissed the charge.



The head of the Harbour Bridge Traffic Alcohol Group, Grant Miller, said he was "a bit struck back" by the judgement.



"That 10 minute period is for people to do with as they wish." Sometimes they phoned people.



Mr Mead has declined to comment.



He had been put on restricted duties at the Counties Manukau police district headquarters and Counties Manukau Acting District Commander Superintendent Nick Perry said Mr Mead could face police disciplinary procedures.



"An employment inquiry is under way in respect of Detective Constable Mead's conduct on the night in question," he said.