The Queen and Duke of Edinburgh yesterday attended a church service amid tight security after starting their Christmas break.
More than a dozen uniformed officers kept a close eye on onlookers watching the couple arrive for the service at St Mary Magdalene church on the Queen's estate at Sandringham, Norfolk.
Officers checked the pockets of visitors arriving outside the church. Estate signs warned visitors that picture-taking was not allowed and police warned onlookers not to use cameras.
Around 50 people gathered to see the royal couple, who were driven to and from the church from nearby Sandringham House.
The royal couple arrived in Sandringham last week and will stay until the new year.
Meanwhile, bosses at a gift shop on the royal estate where the Queen is spending Christmas appear unsure whether Prince William's future wife should be called "Catherine" or "Kate" Middleton.
Royal wedding souvenirs on sale at the gift shop on the estate in Sandringham, Norfolk, give both versions.
A 4.99 paperweight and a 50p postcard "commemorate" the wedding of William and "Catherine Middleton" on April 29.
But an 8.99 2011 calendar is captioned "Prince William & Kate Middleton".