Dunedin police have echoed the concerns of their colleagues elsewhere that ‘‘every major criminal investigation'' will be affected by telephone companies no longer storing phone data.
Dunedin area commander Inspector Dave Campbell said police used recordings of text messages and phone conversations as a major crime-fighting tool.
It was ‘‘unfortunate'' that was unlikely to continue unless legislation changed, Insp Campbell said.
New Zealanders send 640 million texts a month and, although those texts can be intercepted, archives can no longer be retrieved.
Vodafone stopped archiving about a year ago, and Telecom stopped more recently.
Insp Campbell said Operation Harbour, a large-scale undercover crackdown on the drug scene in Dunedin over two years, was the largest electronic operation using interception devices in Dunedin in at least 10 years.
Dozens of people under suspicion of drug dealing had their cellphones tapped and their text messages intercepted during the operation.
So far, the police operation has netted 69 offenders who have committed 400 offences.
They have been sentenced to a combined total of 42 years in prison.
Text messaging was a ‘‘big part' of Operation Harbour, Insp Campbell said.
Before police could tap a telephone, they required a warrant signed by a High Court judge.
They needed to lodge a detailed application with sufficient evidence to satisfy the judge that those whose conversations were to be intercepted were involved in criminal activity.
Once signed, the warrant was valid for 30 days, but it could be renewed.
Vodafone and Telecom have said the storage of text messages had become too expensive and time consuming.
Police Association president Greg O'Connor told NZPA the companies had a social responsibility to store cellphone records.
