A police officer resigned late last year after being investigated for theft in the aftermath of the February 2011 Christchurch earthquake.
It was alleged that three sets of sunglasses were taken from a cordoned-off suburban shop by an officer from the North Island.
Assistant Commissioner for the southern region, Dave Cliff, said the matter was investigated as soon as it was brought to police notice.
"We are very clear that any allegations against police must be investigated thoroughly and promptly. We demand the highest ethical standards from all police officers and police employees.''
An inquiry was initiated immediately and was conducted by senior police investigators. The constable was suspended once evidence of his involvement emerged. He did not admit the theft.
Mr Cliff says legal advice was received that there was not enough evidence that could lawfully be put before a court to prove a charge of theft.
"Fingerprint evidence was not able to be put to the court. Officers' fingerprints are recorded for elimination purposes, but it is not lawful for these to be used for any other purpose. As a result the decision was made, reluctantly, that charges could not be brought against the constable.
"Police then initiated an internal disciplinary process. This is a transparent process between the employer and employee _ and culminated in a disciplinary hearing, conducted by an independent senior barrister.
"The constable has subsequently resigned from police prior to the conclusion of this process.
"I am satisfied that police investigated promptly and fully, and that we have taken every possible action against the officer.
"The officer was the subject of a full investigation and his police career is now over.
"The tragedy arising from this investigation is that literally thousands of police officers from New Zealand and overseas worked for months to help the people of Christchurch _ whether in terms of rescue, family liaison, perimeter security or mortuary duties for instance.
"The actions of this individual have tainted that effort.''