An American artist paid 730,000 US dollars (£561,000) for a Banksy artwork painted on the side of a North London Poundland – then vowed to whitewash it.

Slave Labour depicts a young child on his knees at a sewing machine, producing a string of Union Jack bunting.

It was painted on the side of a bargain store in Wood Green in 2012 and is believed to be a protest against sweatshops used to manufacture souvenirs for the London Olympics.

Slave Labour was sold by Julien’s Auctions in Los Angeles on Wednesday and was bought by American artist Ron English, who revealed he plans to whitewash it in protest against street art being bought and sold.

He told the Press Association: “My idea for this painting is to whitewash it for my good pal Banksy, I only wish I could’ve spent more money for it.

“I’m going to paint it white again, I’m done. This is a blow for street art. It shouldn’t be bought and sold.

“I’m going to paint over it and just include it in one of the walls in my house. We’re tired of people stealing our stuff off the streets and re-selling it so I’m just going to buy everything I can get my hands on and whitewash it.”

Nuart festival 2012
Ron English is an acclaimed American street artist (Yui Mok/PA)

The painting sold for 600,000 US dollars plus the buyers premium, bringing the total to 730,000 US dollars, Darren Julien, of Julien’s Auctions said.

English, who said he had spent time in Palestine with Banksy, added: “Then off course I’ll sell the whitewash painting for a million dollars. I’m crazy but I’m not stupid.”

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Going, going, gone…

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In October, a Banksy piece sold in London partially shredded itself after the hammer came down.

Girl With Balloon, one of the mysterious artist’s most famous works, sold for £1.04 million before the canvas passed through a shredder installed in the frame.

The buyer later confirmed they were going through with the sale.