An anthropologist believes they have discovered the final remaining British woman who hasn’t inexplicably had sex with Boris Johnson.

The discovery is one-in-thirty-million and is being considered the human equivalent of finding a needle in a haystack.

‘Or a needle in Boris’ hair, if you like,’ said the anthropologist.

The woman, who wishes to remain anonymous out of concerns for her virtue, was found in London and has since been moved to a safe location where Boris dare not go.

Rumours that the location is along the Irish border are unconfirmed at this time.

Johnson himself has refused to deny having slept with the majority of women in Britain, citing a hazy memory and a lack of anything better to do.