Google has been rocked by news of an office romance that is being blamed for a split between co-founder Sergey Brin and his wife, and the sudden resignation of another senior male executive who was the former boyfriend of Brin's new love interest.

The fallout could get even more complicated because Brin's wife of six years, Anne Wojcicki, is the sister of the Google senior vice president in charge of product management ads and commerce, Susan Wojcicki.

It was Susan Wojcicki’s garage in Menlo Park, Silicon Valley where Brin and his co-founder Larry Page, moved to run their fledgling company in September 1998.

Susan, who has been called "the most important Googler you've never heard of", was employee number 18 at Google. She is currently the highest-ranking female employee at Google.