Thirty five psychologists have resigned from the children's gender-identity service in London in the last three years, Sky News research suggests.
Six of those have now raised concerns about hormone treatment being given to children with gender dysphoria, a condition where a person experiences distress due to a mismatch between their biological sex and their gender identity.
A psychologist, who wished to remain anonymous, said: "Our fears are that young people are being over-diagnosed and then over-medicalised.
"We are extremely concerned about the consequences for young people... For those of us who previously worked in the service, we fear that we have had front row seats to a medical scandal."
The Gender Identity Development Service (GIDS) at the Tavistock and Portman NHS Foundation Trust is where children with gender dysphoria are treated on the NHS.
GIDS had 2,590 children referred to them last year, compared with just 77 patients a decade ago.
Comment: As doctors and psychologists forget the maxim of 'first do no harm' in favor of their careers and financial rewards, children are being led to make choices that will have permanent and in many cases deleterious effects on their physical and emotional well-being. At some point there will be a reckoning and the legal profession will have a field day.