If you've received an unexpected call lately from an overseas number that you don’t recognise, you’re not alone. The ‘missed call’ or Wangiri scam – Japanese for ‘one ring and cut’ – has been on the increase over the last few weeks. New Zealand targets of the scam report they have received calls from numbers beginning with 0088 or 002, which originate in the African country of Chad, but calls are being made from other countries too.

The Wangiri scam works by when fraudsters hack the system that manages the transfer, connection and payment of customer calls across international mobile networks. When they call you, they are hoping you call them back because if you do they will be fraudulently collecting the cost of the call you are making to them via the system they have hacked.

Vodafone advise simply ignoring any unexpected calls from international numbers that you don’t recognise. Let the call go to voicemail and definitely don’t call them back.