A man claiming to work for the NHS gave an elderly woman a fake coronavirus vaccine and charged his victim £160.
Detectives hunting the suspected conman said he “may endanger people’s lives”.
The 92-year-old victim allowed him into her home in Surbiton, south-west London, on the afternoon of Wednesday, December 30.
He said he was from the NHS and there to administer the Covid-19 vaccine.
The elderly lady said she was jabbed in the arm with a “dart like implement” before being charged £160 which the fraudster said would be refunded by the NHS.
The City of London Police said it is not known what substance, if any, was administered, but she has no ill effects after a being checked out at a local hospital.
Detective Inspector Kevin Ives said: “This is a disgusting and totally unacceptable assault on a member of the public which won’t be tolerated.
“We are appealing to anyone who may have information that could assist us in identifying this man to get in touch.
“It is crucial we catch him as soon as possible as not only is he defrauding individuals of money, he may endanger people’s lives.”
Images released by police show the suspect dressed in a navy blue tracksuit with white stripes down the side.
The images are from a second visit he made to the woman’s home in Kingsmead Avenue on Monday, when he asked for another £100.
He is described as a white man in his early thirties, who is around 5ft 9 inches tall, of medium build, with light brown hair that is combed back and speaks with a London accent.
Anyone with information is asked to call 101, quoting reference 3042 and the date Jan 7 2021, or contact Crimestoppers.