A painting owned by Queen Elizabeth has been revealed to be a lost work by the Italian master Caravaggio.
The picture, which has been in the royal family's possession for around 400 years, and, obscured by varnish and dirt, it was dismissed as a copy.
The work was left in a storeroom at Hampton Court for decades until experts from the Royal Collection set about restoring the piece.
They spent six years studying the painting and have now announced that it is The Calling Of Saints Peter and Andrew- a real Caravaggio and one of only 50 surviving canvases by the 17th-century artist.
The work will now feature in the major "Art of Italy" exhibition next year at Buckingham Palace's The Queen's Gallery.
Reports estimated the painting, which was first bought by Charles I, sold and then reacquired by Charles II, could be worth more than £50 million.
The queen cannot sell items from the Royal Collection. She holds them in trust on behalf of the nation, as part of Britain's heritage.
Caravaggio's Taking of Christ- missing for 200 years - was discovered hanging on a wall in the Jesuit House in Dublin in 1990.