The mystery behind the 3-inch scar on Kate Middleton that caught the attention of people during the recent black-tie charity event at Clarence House has finally been unfolded. The Daily Mail reported that the scar was due to a sporting accident while the Duchess was studying at Malborough School in Berkshire.

According to Palace sources, the three-inch scar was from a childhood operation. However, they refrained from revealing more, citing privacy reasons. However, the truth was revealed by some of Kate's childhood friends who knew the truth of the mysterious scar.

The prominent scar, on the side of her left temple, was quite visible during the event at Clarence House.

The scar could have been from anything, including a birthmark, trauma, neurosurgery or a benign growth of the skin. You can't tell anymore than that, ABC news quoted Dr. Roy Geronemus, Director of the Laser & Skin Surgery Center of New York as stating.

During the black-tie event, the Duchess looked stunning in a silver evening gown by designer Amanda Wakeley. As per reports, the vintage gown is from the designer's Winter 2006 collection.