A reward of £20,000 was offered today to bring the first person in the UK to justice for the barbaric ritual of female circumcision.
It is feared that up to 66,000 women and girls in the UK are at risk of genital mutilation, a tradition traced back to many African nations.
One London health specialist said she is treating up to 500 women every year for health problems linked to the practice.
But police said no one has ever been prosecuted despite specific new legislation outlawing both those who undertake the procedure and arrange it.
Launching a campaign aimed at raising awareness of the practice, officers from the Metropolitan Police's child abuse unit said it was a hidden crime.
They warned that many children are taken overseas during the summer holiday to undergo the procedure.
Officers added there is growing evidence that genital mutilation is also taking place among immigrant communities in the UK.
Detective Chief Superintendent Alastair Jeffrey said the true impact of female circumcision is impossible to measure.
He said: "The timing of this campaign is for one good reason: so we can get in before the summer holidays, a time when young girls are taken abroad and subjected to genital mutilation.
"We want to get the message over now because if we do we will be able to prevent a number of children having this brutal attack on them."
Defending the campaign, he insisted: "This is child abuse. It is not an attack on anyone's culture, it is an attack on anyone who commits this horrendous abuse of children.
"This is an appeal to communities themselves to eradicate this practise from within. It is about self-policing. It is recognising the fact that this is abuse."
Female circumcision is most common among people from African and some Middle Eastern nations.
Countries with the highest recorded rates include Egypt, Ethiopia, Somalia and Sudan, according to health charities.
The term female circumcision covers a range of procedures from minor symbolic cuts to the genitals to attacks that involve complete amputation of external body parts.
Girls as young as just several weeks old are attacked by untrained people, sometimes family members, who use non-medical equipment without anaesthetic.
Police said instruments such as rusty tin can lids, razor blades and broken glass have been used to cut them, and thorns used to stitch up the wounds.
The procedure can lead to both short and long term health problems, while some girls have died from infection.
The perpetrators undertake it for various reasons including the belief that it is done for chastity, to make a girl into a woman or for religious beliefs.
In the UK, any practitioner or person who helps someone else to undertake it, could face up the 14 years' imprisonment under the Female Genital Mutilation Act 2003.
Detective Inspector Carol Hamilton has been investigating female circumcision since 2004.
She said some immigrants in the UK may bring practitioners from their home country to mutilate several children because it is cheaper.
Ms Hamilton said children do not just receive terrible physical injuries, but can suffer mental scars for the rest of their lives.
Midwife Comfort Momoh, of Guy's and St Thomas' Hospital, in central London, is one of the people in the UK who specialise in treating victims.
She said she treats between 400 and 500 women every year and performs two or three "reversals" every week.
Ms Momoh said the practise is particularly prevalent in poorer boroughs in the capital, including Hackney, Haringey, Camberwell, Peckham and Bermondsey.
The police reward will be paid to anyone who can provide information about someone undertaking genital mutilation in the London area that leads to a conviction.
Mr Jeffrey said: "It does happen in London. It is not just about children being taken out of the country. It is actually happening in London and we need to stop that."Reuse content