Kate Middleton is using the Queen's legal team to take action against paparazzi who snapped her playing tennis on Christmas Day.
The pictures - which were published in a German magazine - invade her privacy, she says.
A spokesperson for Prince William, who supports her move, says: "The point is it occurred on Christmas Day, a day most people regard as private."
Kate spent the day with her family at Restormel Manor in Cornwall.
Photo: © Rex