Wowsers!

From the Telegraph:

The Calling of Saints Peter and Andrew, owned by the Royal Family for almost 400 years, has lain unloved and seldom seen in a storeroom at Hampton Court for decades. Misattributed as a copy of a Caravaggio by an unknown hand, it was valued in thousands rather than millions.
The Royal Collection, whose experts have cleaned, restored and studied the picture for six years, declared yesterday that it is authentic and one of only around 50 surviving canvases by the Italian master. "I am convinced it is by Caravaggio," Desmond Shawe-Taylor, Surveyor of the Queen's Pictures, said. "We are extremely excited, it's the most important discovery in the collection in the last decade."
The painting was bought by Charles I in 1637 and after being sold with most of the Royal Collection during the Commonwealth, it was re-acquired by Charles II.
Years of grime, varnishing and zealous over-painting to cover up damage convinced generations of art historians that it was of little merit. It was recently valued at "a few tens of thousands of pounds", mainly because Charles I's stamp was on the back.
Competing with 7,000 other paintings in the collection, it has not been hung in a royal palace for years and no gallery has asked to borrow it.
It will now be shown in Rome at the end of the month in honour of the Italian curator, Prof Maurizio Marini, who first suspected that there might be more to the work.