TOKYO, June 28 -- Japan's newest police chief doesn't patrol the streets, carry a firearm or even exist in the real world.

Instead, she appears on YouTube with the face and voice of a young woman, calmly explaining why anyone claiming to be a police officer over a video call is almost certainly trying to steal your money.

Her name is AIko, and she is the Osaka Prefectural Police's latest weapon against a fraud epidemic that drained victims of a record more than US$2 billion (RM8 billion) last year - a crisis authorities say is increasingly fuelled by social media and sophisticated criminal networks operating across South-east Asia.

Introduced in late May, AIko's name combines the abbreviation for artificial intelligence with "ko", a co...