New Zealand police are unsure how widespread the latest online scam depicting its logo has spread.

The scam had blocked certain electronic devices "for safety reasons" and told viewers they were under investigation for porn-related and copyright-related laws.

A national police headquarters spokesperson said it had appeared locally in Waikato, but could not say how far beyond this it had gone.

But they said the public needed to be aware that police would never give electronic notification of such an investigation.


"It has appeared on all kinds of devices from home computers to smart phones. If someone should find a message like this on their device they should delete it."

The spokesperson said it was wise to delete all emails from unknown senders and any with unexpected attachments.

Waikato police had this week warned people about the scam popping up people's electronic devices.

It went on to tell the user they'd been accused of the viewing, storage and dissemination of pornography, including child pornography, zoophilia and rape, along with suspicion of violation of copyright-related laws and downloading pirated music.

Te Awamutu police posted a screen grab of the scam on its Facebook page and assured followers it was unauthorised.

"I would like to draw to your attention a scam that has appeared on our victim's phone," police wrote. "As you can see in the photo the New Zealand Police logo is prominently displayed.

"Be assured we the police would not alert you electronically that you are under investigation. If you were under investigation for these sort of crimes, the first you will know about it will probably when we turn up to your house with a search warrant.

"If you are into these sort of crimes, you better put the kettle on."

Several followers have replied, having either already seen it or having it appear on their phone after reading the post.

One woman said it ruined her son's phone, while another woman said it popped up on her and her husband's phone at the same time.

Another person said it had just popped up and wanted help to remove it.

Scam warnings are posted on the Department of Internal Affairs (DIA) website here.