Blaise Metreweli was announced as the new chief of MI6 earlier this month – becoming the 18th person to take on the role in the organisation’s 116-year history.
The Daily Mail reported her grandfather Constantine Dobrowolski had previously defected from the Red Army to become a Nazi informant in the Chernihiv region of Ukraine.
The newspaper said German archives showed Mr Dobrowolski was known as “The Butcher” or “Agent No 30” by Wehrmacht commanders.
Reports also said the Nazi spy chief had a 50,000 rouble bounty placed on him by Soviet leaders, and was dubbed the “worst enemy of the Ukrainian people”.
Ms Metreweli’s grandfather also sent letters to superiors saying he “personally” took part “in the extermination of the Jews”, the newspaper said.
Ms Metreweli will take over as head of MI6 from Sir Richard Moore, a senior civil servant who will step down in the autumn after five years in the role.
Commonly referred to as C, the chief has operational responsibility for MI6, and is the only publicly named member of the organisation.
She first joined the service as a case officer in 1999 and has carried out operational roles in the Middle East and Europe.
In her new post, she will be accountable to the Foreign Secretary.
