School pupils have discovered a potentially pricey piece of art in one of their stationery cupboards.

Girls at Roedean, in Brighton, believe they have found a painting by renowned landscape artist John Constable.

The picture was nestled among pens and exercise books.

It was covered in bubble wrap and it is thought it may have been in the cupboard for 64 years.

It is entitled The Chain Pier Brighton In A Gale and is signed on the back – the signature resembles that of Constable.

Senior deputy head principal of Roedean Richard Chamberlain said it was discovered by a couple of pupils who were waiting to attend a school event outside a room that used to be the headmistress’s office.

They wondered what was in there and ventured in to have a look – and found the small package at the back of the room with the painting inside.

Constable used to live in Brighton – in Sillwood Road – in the 1820s.

On the back of the painting there are details of it having been sold at Christie’s auction house in London in 1909.

Sixth formers Eris Kennish, 17, Mary McHarg, 18, and Amirah Mehdi, 17, travelled to Christie’s with Mr Chamberlain to try to establish whether the painting was a genuine Constable.

Experts at the auction house were divided – one said it was authentic while the other was unsure.

But if it is a genuine Constable it could be worth up to £1 million.

Eris said: “It all seems like something out of a storybook that the painting was found hidden away like this.

“It’s just amazing.

“It’s great that it was some of the girls who discovered it – it makes it even more exciting.”

Mary said: “I’m a bit of an art history nerd so it’s really interesting and exciting that a piece of art like this was just sitting here in the school I go to.

“I couldn’t believe it when I heard.”

Amirah said: “When the three of us went up to Christie’s to find out about the painting, it felt like a real adventure.

“It was really interesting to see how they operate.

“But we still don’t know for sure as the experts’ opinion was divided.

“The mystery of the painting remains.”

Now the school is seeking further help in establishing the provenance of the painting.

The staff hope that if and when it is authenticated it can go on display at the Brighton Museum.

John Constable was born in Suffolk in 1776 and became a famed British landscape artist.

He is best known for his 1821 piece The Hay Wain