New research has revealed an unexpected link between King Richard III and a Scottish saint.

The monarch's private prayer book, which was placed on his coffin during his re-interment last year, contains a prayer to St Ninian of Whithorn in the infamous king's own handwriting.

Researchers are unclear as to how and when Richard III encountered the Scottish saint, bit it is believed it was during his residence at Carlisle when he was warden of the Western Marches.

A spokeswoman for historical society the Whithorn Trust said the discovery showed that the king had a personal spiritual life quite different to what he displayed publicly.

She said: "We were fully aware of the devotion to St Ninian by Scottish kings and queens, but the English cult of St Ninian, particularly by Royal devotees, has remained comparatively unexamined until now.

"It is interesting that Richard III's worship of the saint appears to have belonged to his private spiritual life and to his concern for the immortal souls of his family, and does not appear to have been displayed publicly for political purposes.

"We are looking forward to further research, which intriguingly might reveal a pilgrimage to Whithorn by this most famous of Plantagenets.

"Researchers tell us that there may be a time in the 1470's when this might have been possible and certainly the Solway was the route for English pilgrimage to Whithorn, via its port at the Isle of Whithorn."

The trust has now teamed up with the Scottish branch of the Richard III Society to launch a new project looking at the connection between the King and St Ninian.

Edinburgh resident Philippa Langley launched the Looking for Richard project in February 2009, ultimately resulting in the discovery of the king's remains in a council car park in Leicester in August 2012.

The monarch, who was King of England from 1483 until his death in 1485, at the age of 32, in the Battle of Bosworth Field, was re-interred at Leicester Cathedral on March 22, last year.