The Metropolitan Police is investigating concerns that stem cell injections are being offered to children as a cure for autism in south east London.
The Royal Borough of Greenwich said that it was aware of concerns that an "individual claiming to be a doctor" was planning to visit the UK to offer "dangerous, experimental procedures on children with autism".
Stem cell therapy is used in the treatment of conditions like blood cancers or burns, but it is not approved as a treatment for autism.
There is no cure or treatment for autism, according to the National Autistic Society. Instead, charities recommend a combination of behavioural, mental and financial support.
A spokesperson for Greenwich Council said the fake doctor is "proposing the transfer of bone marrow and spinal fluid to the brain by injection".
They said: "This unlicensed procedure poses a significant threat to life and there is no evidence of any benefits.
"The safety and welfare of our children and young people is of the utmost importance."
They added: “The limited intelligence available suggests that the individual plans to arrive in the UK on 22 April 2024. Anyone in Greenwich approached by this individual should not engage with them and inform Greenwich LADO at childrens-lado@royalgreenwich.gov.uk as a matter of urgency.”
A spokesperson for the Met Police told the BBC: "Inquiries are ongoing to establish the identity of the person(s) behind these adverts and to confirm where they are based.
"There is no evidence to suggest that the person(s) behind these adverts has treated anybody in the UK."
No arrests have been made, the force said.
A spokesperson for the National Autistic Society told the broadcaster: "There is very little evidence about stem cells and autism. There are also concerns about the regulation of stem cell procedures, which could be painful or even hazardous depending on how they are administered.
"We would encourage anyone looking for advice or guidance about autism to seek reliable and safe information from our charity, the NHS and the National Institute for Health and Care Excellence."
Clinics have claimed, without evidence, that expensive stem cell therapies can help patients with other conditions including dementia, multiple sclerosis and cerebral palsy.
