Vandals have smashed a valuable piece of artwork expected to raise thousands of pounds for a children's charity.

The Endless Carnival, part of the Dream Jar project and designed by artist Caio Locke, was smashed and its contents stolen from outside the Gallery of Modern Art in Glasgow on Thursday morning.

Passers-by then started putting rubbish, including an empty Irn Bru bottle, into the broken jar on Royal Exchange Square.

The artwork was placed outside the gallery as part of a UK-wide display to coincide with the release of the Steven Spielberg film the BFG.

Mr Locke said: "The Dream Jar project was intended to encourage children in the pursuit of their imagination so it is disappointing to hear about artwork vandalism which to my mind has exactly the opposite effect."

The jars also mark the 100th anniversary of Roald Dahl's birth, with several positioned around famous galleries and landmarks in London.

Each depicts the childhood dreams of 50 famous people, including the Duchess of Cornwall, Professor Stephen Hawking and astronaut Buzz Aldrin.

The artworks are to be auctioned off to raise money for Save the Children and for a specialist nursing programme support by Roald Dahl's Marvellous Children's Charity.

Natasha Parker at Save the Children said: "We are incredibly disappointed to learn that Caio Locke's The Endless Carnival Dream Jar, which was a beautiful and unique piece of art, has been taken from the city centre and will sadly no longer be a part of The BFG Dream Jar Trail.

"It was set to raise thousands for Save the Children via the live online auction at www.paddle8.com/bfg to help vulnerable children around the world get the chance to make their dreams come true.

"We are appealing to the public to continue supporting Save the Children and the Dream Jar Trail by texting DREAM to 70008 to donate £5 to help recoup the funds lost, or to go to Paddle8 where they can read the stories on all our dreamers and bid for the other Dream Jars."

A spokesman for Glasgow City Council urged anyone with information to contact police.

He said: "We were approached by the organiser of this project and asked to find a suitable location in the city.

"It's deeply disappointing an artwork intended to help vulnerable children has been vandalised. "We urge anyone with information to contact police."