The Australian Communications and Media Authority (ACMA) has received complaints about the scam messages, which it says come from overseas.

The messages aim to frighten recipients into passing on money, credit card details and personal information to the scammers, according to ACMA.

This is an example of the messages: “I am about to kill you. If you want to live, contact (xxxxxx.com) to get information on what you will have to do to live. If you ignore this message, you will die!”

Chris Chapman, chairman of ACMA, said people should definitely not reply to the messages, and should report them instead.

“These threats are a particularly nasty type of scam,” Mr Chapman said, leaving some people distressed

Recipients are advised to contact ACMA by telephone or over the internet.

SMS death threats a scam – watchdog | National Breaking News | News.com.au