Crime writer Agatha Christie's murder mystery novels are getting a new outing - as stamps.
Royal Mail is issuing six stamps to mark the centenary of the year Christie wrote her first detective novel, The Mysterious Affair at Styles, which introduced her much loved Belgian detective Hercule Poirot to the world.
The stamps come complete with hidden clues and references, printed in special inks and microtext, to murders and key scenes in the famous novels.
Novels featured in the stamps - which will be available for a year - include Murder On The Orient Express, The Body In The Library, And Then There Were None, The Murder of Roger Ackroyd, A Murder Is Announced and The Mysterious Affair At Styles, which she wrote in 1916 but was published in 1920.
Amateur sleuths will be able to use UV light, body heat and a magnifying glass to uncover hidden elements and key scenes in the stamps.
Clues and features include a figure, half-hidden and wielding a knife, letters, the names of the suspects and Poirot himself.
Designed by Jim Sutherland, the stamps launch today, the same day as the best-selling British author's birthday.
Royal Mail said it would also provide a special handstamp on all mail posted in a postbox in Christie's town of birth, Torquay in Devon, for five days from September 15 to 19.
The British author, who died at the age of 85 on January 12 1976, is the best-selling novelist in history, outsold only by the Bible and Shakespeare, with more than two billion copies of her books sold worldwide