Britain’s first prosecution for female genital mutilation was a landmark case of enormous symbolism.

But the verdict came down to a very narrow issue - exactly how far did Whittington Hospital doctor Dhanuson Dharmasena sew up the woman after she gave birth.

Prosecutors had argued that, under pressure from another man Hasan Mohamed, the 32-year-old doctor had sewn up the woman “considerably”.

They claimed he stitched her labia together, obstructing the urethra, and that this amounted to “reinfibulating”, re-doing her childhood FGM.

However, Dharmasena insisted he only carried out a single figure of eight stitch to stop the blood which she had been oozing for around 20 minutes.

And he said he left AB with more room in that part of her body.

The Female Genital Mutilation Act 2003, under which the case was brought, allows for key exemptions to prosecution.

It states no crime is committed if a registered medical practitioner performs the procedure because it is “necessary” for the patient’s physical or mental health, or for purposes connected to labour or birth.

After extensive legal argument on the meaning of the Act - never before tested in a court of law - it was agreed the case hinged on exactly how far the stitches went.

If jurors believed the prosecution that the stitches were longer and left AB far more closed, then they should convict.

But if they believed the doctor when he said he sewed one small stitch at the apex, then the judge directed the jury he must be cleared.

If they thought the stitches fell somewhere between the two accounts, they must acquit.

Jurors took less than 30 minutes to find Dr Dharmasena not guilty of FGM in what was a landmark trial.