Michelle Obama made headlines in 2009 when she broke protocol and hugged Queen Elizabeth during a visit to Buckingham Palace as the First Lady of the United States. The monarch returned the hug and the pictures clicked during a G20 reception at the Palace showed the two ladies standing with their arms around each other.

The hug shared between the then FLOTUS and the monarch had created a buzz in the media about a supposed breach of royal protocol, but none of the sides made a clarification. Now 10 years later, Angela Kelly, the dresser and a close confidante of Queen Elizabeth, has opened up about the incident. She said the hug was "instinctive" and a gesture of "affection and respect for another great woman."

"When human instincts kick in, sometimes this is absolutely the appropriate thing to do," Angela Kelly writes in her new book "The Other Side of the Coin: The Queen, The Dresser and the Wardrobe". The book had received the approval of the monarch as well, reports Hello.

"There are certain things that are understood to be accepted protocol when it comes to interacting with Her Majesty. Supposedly, you should never put your arm around the Queen, for example, but when human instincts kick in, sometimes this is absolutely the appropriate thing to do," Kelly said.

Kelly who has worked with the queen for 25 years added that the "Queen has the ability to make everyone feel so relaxed that sometimes it feels instinctive to be tactile with her." She said the same thing happened during Michelle Obama's state visit with husband and then US President Barack Obama in 2009.

"Much has been made about the meeting between Michelle and Her Majesty, when an instant and mutual warmth was shared between these two remarkable women, and protocol was seemingly 'abandoned' as they stood closely with their arms around each other's backs," Kelly wrote.

She explained there is no protocol to follow when queen feels the instinct to show affection and respect for another great woman and wrote the matter is truly about human kindness.

1 April 2009: US President Barack Obama and his wife Michelle meet with the Queen and Prince Philip at Buckingham Palace AFP

"In reality, it was a natural instinct for the Queen to show affection and respect for another great woman, and really there is no protocol that must be adhered to. When fondness is felt or the host of a State Visit goes to guide Her Majesty up some steps, it truly is about human kindness, and this is something the Queen will always welcome warmly. Anyone who is close to Her Majesty is not a threat and is certainly trusted," Kelly writes in the book.

In the past, Australian prime minister Paul Keating and his successor John Howard were accused of breaking the royal protocol during their respective visits to Queen Elizabeth, when they put an arm around her.