Female genital mutilation (FGM) is increasingly being performed on babies and infants in the UK - In one report, in Yorkshire, a victim was just one month old.
FGM expert and barrister Dr Charlotte Proudman said it was "almost impossible to detect" as the girls were not in school or old enough to report it.
In one report, in Yorkshire, a victim was just one month old.
The National FGM Centre said it was "not surprised" that victims may be younger now.
Charity Barnardo's and the Local Government Association - which together run the centre - said its community engagement was "key to protecting girls".
Their comments follow the first UK conviction for FGM.
The mother of a three-year-old girl was found guilty at the Old Bailey on Friday of mutilating her daughter. Her partner was acquitted.
FGM includes the partial or total removal of the female external genitalia or other injury to the female genital organs for non-medical reasons.
Dr Proudman said there was "a lot of anecdotal data which shows FGM is now being performed on babies.
"These girls are not at school, they are not at nursery, and so it's very difficult for any public authority to become aware," she added.
"By performing it at such a young age, they're evading the law."
In response to a Freedom of Information request, West Yorkshire Police said a quarter of its FGM reports (17) between 2015 and 2017 involved victims aged three or under.
The National FGM Centre said there was "anecdotal evidence from some communities that FGM laws can be circumnavigated by performing the procedure on girls at a much younger age".
"The girls are unable to report, the cut heals quicker and prosecution is much harder once evidence comes to light and the girl is older.
"There needs to be much greater recognition of this issue across different areas of the UK."
'Worried about being branded racist'
Experts say authorities need a more joined-up approach when dealing with FGM.
It is claimed children's services can be unsure when to intervene. Doctors are not always reporting it to the police - and even if they do, officers do not always know what to do.
"People are concerned about cultural sensitivities, worried about being branded racist, and it's being performed on a very private area," Dr Proudman said, explaining why it has taken many years for the first UK conviction to arrive.
Figures seen by the Victoria Derbyshire programme show that 939 calls were made to emergency services to report FGM between 2014 and 2018.
But the Crown Prosecution Service has only received 36 referrals for FGM from the police since 2010.