A senior judge has said that circumcision "significantly harms" baby boys.
Sir James Munby, president of the Family Division, made the comments during a case in which Muslim parents had been accused of subjecting their three-year-old daughter to FGM.
Giving judgment in the case, Sir James said FGM caused significant harm to girls, adding: "The same must be so of male circumcision."
However, he added that it was a far cry from the "great evil" of FGM, and that the courts were "prepared to tolerate" circumcision carried out for religious or cultural reasons.
Sir James said: "FGM has no basis in any religion; male circumcision is often performed for religious reasons.
"FGM has no medical justification and confers no health benefits; male circumcision is seen by some - although opinions are divided - as providing hygienic or prophylactic benefits.
"Be that as it may, 'reasonable' parenting is treated as permitting male circumcision."
A spokesman for Milah UK, a campaign group protecting brit milah, said that they would contact Sir James in response to his remarks.
He said: "We will be writing to [Sir James] to respectfully ask for clarification of the statement. However, we note Sir James has been clear of the distinction between male circumcision and Female Genital Mutilation."
Last week, a Danish study published in the Journal of the Royal Society of Medicine claimed that circumcision on boys under the age of five could double the risk of them developing autism spectrum disorder (ASD).
The chairman of Milah UK, Professor David Katz, said the research was "far from convincing".
"Correlation does not equal causation," Professor Katz said. "There is general agreement that, in people suffering from an ASD, there are abnormalities that can be identified in brain structure and/or function."
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