Bob Dylan's artwork is going on display at the National Portrait Gallery in London.

A dozen new pastel portraits will go on show later this month in an exhibition, Bob Dylan: Face Value.

Singer-songwriter Dylan, 72, has sketched and drawn since childhood and began to paint in the late 1960s. He first exhibited his work six years ago.

His latest pastel portraits have not been shown anywhere before.

Unlike other subjects, who are drawn from British public life, in the National Portrait Gallery, Dylan's portraits are "an amalgamation of features the musician has collected from life, memory and his imagination and fashioned into people".

Sandy Nairne, director of the London gallery, said: "Bob Dylan is one of the most influential cultural figures of our time. He has always created a highly visual world either with his words or music, or in paints and pastels.

"I am delighted that we can now share these 12 sketches which were made for display at the National Portrait Gallery."

Art historian John Elderfield, who helped bring the display to the Gallery, said that the paintings were the "products of the same extraordinary, inventive imagination" behind Dylan's songs.

In 2008, The Halcyon Gallery in London featured Dylan's drawings and sketches from periods on the road between 1989 and 1992.

Bob Dylan: Face Value, a free exhibition, runs from August 24, 2013 to January 5, next year at the National Portrait Gallery.