Offenders are increasingly using equipment to block mobile phone signals to avoid detection, says the Ministry of Economic Development (MED).
The warning comes after a Kapiti Coast man was fined $2000 in Porirua District Court last month after he admitted supplying radio jamming transmitters and "transmitting outside the terms of his radio licence''.
The man was charged after police found the transmitters during a drug raid.
"This is a good example of government agencies working together to reduce crime in the community,'' national compliance manager for MED's Radio Spectrum Management Chris Brennan said.
"Radio jammers are increasingly being used as part of criminal activity,'' Mr Brennan said.
