A rare 1623 prayer book that belonged to Father John Huddleston, who converted King Charles II to Catholicism on his deathbed, has sold for £6,900 in an online auction.

The book, which includes the priest's signature and is traditionally known as a missal, was owned by a family from the Wirral who bought it in a Liverpool bookshop in the 1950s.

The auctioneer, John Crane, said the sale was "hotly contested" by 25 bidders and the book's buyer is a public institution.

"All we can say about the buyer is despite there being many private bidders and collectors, it was eventually bought by a public institution, who I'm sure in due course will put it on display."

Father Huddleston was a Roman Catholic monk who arranged for Charles II to escape after the English Civil War. Two years after the execution of his father, Charles I, the priest's actions are thought to have rescued the young monarch's life.

 He also helped the king convert to Catholicism on his deathbed in 1685.