Mycroft Holmes
From Tardis Wiki, the free Doctor Who reference
Mycroft Holmes was the brother of Sherlock Holmes and an ally of Bernice Summerfield. (BFBS: The Adventure of the Diogenes Damsel)
Biography
The Seventh Doctor, Ace and Benny met Mycroft while he was in the employ of the British government. (PROSE: All-Consuming Fire)
In 1916, Mycroft was working for the British government during World War I. (IW: The Found World)