Three paintings by Van Gogh, Picasso and Gaugin were stolen in a raid on an art gallery in the North of England today.
Staff at Manchester's Whitworth Art Gallery raised the alarm as they prepared to open for the day.
Police were called and a major investigation launched.
It is thought the paintings were stolen some time between 9pm last night and midday today.
A spokesperson for Greater Manchester Police said: "This was a well planned theft and we have launched a major inquiry. We are now trying to piece together what has happened."
The Whitworth Art Gallery is one of the leading galleries in Manchester city centre with outstanding collections of British watercolours and historic textiles as well as excellent work from a number of modern and contemporary artists.
The Whitworth's collection of 40,000 works of art is designated as of national significance by the Government.
Among the works held by the gallery are 12 Picassos and two drawings - Hayricks and The Fortifications of Paris With Houses - by Vincent Van Gogh.
There are no works by Gaugin listed in the gallery's permanent collection.
PA