According to The Sun, three thieves managed to gain access to the 57-room mansion — which boasts both a basement swimming pool and cinema — via the back garden.
They cleared out safes in her dressing room, as well as her husband Jay Rutland's, making off with a haul of precious rings, earrings and a $107k Cartier bangle wedding gift.
The entire raid could not have lasted more than 55 minutes, as in-house security swept the area on the hour; a security guard discovered them on the second sweep, but they still somehow managed to escape with their eight-figure loot.
The brazen raid is even more shocking considering the street is home to several foreign ambassadors and dignitaries, and thus enjoys a permanent police presence.
A spokesman for Tamara told the publication: "I can sadly confirm that there has been a home invasion. Internal security are cooperating with police in this matter. Tamara and family are well but obviously angry and shaken by the incident."
The couple share a five-year-old daughter, Sophia. All three had left the home for the holidays just hours earlier.
Her father Bernie is the former chief executive of the Formula One Group, which manages Formula One racing and controls the commercial rights to the sport; he remains one of the wealthiest men in Britain.
Police are still investigating, and no arrests have yet been made.