Fraud cost Sweden 5.7 billion SEK, around £434 million, with older people among the most common targets.

The campaign features four Swedish celebrities, including 74-year-old Suzanne Reuter, who said people of her generation were often taught to be polite and accommodating, but scammers exploit those traits.

Most scams targeting people over 60 begin with text messages impersonating authorities, banks or companies before victims are persuaded to call a number. Fraudsters then use prepared scripts to create trust, stress and urgency.

Police urged people to hang up if they become suspicious.

National operations leader Robert Öhman said officers would never collect valuables for safekeeping, and urged people to shut the door on anyone making such a request.