LONDON, June 27 -- Britain's incoming MI6 chief Blaise Metreweli is facing uncomfortable scrutiny after revelations surfaced linking her paternal grandfather to Nazi war crimes in Ukraine during World War II.

Metreweli, who is set to become the first woman to lead the Secret Intelligence Service, was widely praised for her intelligence, discretion, and exemplary service record when her appointment was announced earlier this month, according to a report in Mail Online.

But German archives have revealed that her grandfather, Constantine Dobrowolski, was a Nazi collaborator and local intelligence chief in the Ukrainian region of Chernihiv, known for spying and killing on behalf of Hitler's regime.

"Captain Dobrowolski is a convinced oppon...