Selling a Banksy

For nearly a year, the haunting image of a boy hunched over a sewing machine adorned the wall of a Poundland in north London.

It was attributed to the elusive street artist Banksy, supposedly his critique of the Queen's Diamond Jubilee.

Then, in February, it disappeared. Over the course of three days, the graffiti art was carefully prised from the wall of the building - owned by local investment company.

Nobody knows who authorised its removal or why, but the Metropolitan Police told the BBC that there were "no reports of any theft".

Soon, the mural resurfaced in Miami, where it was put up for auction with a guide price of around £450,000, only to be withdrawn at the last minute following a public outcry.

But the story isn't over. It's now appeared for auction again, this time in London - where the minimum bid is £900,000.

Here's my report ahead of the sale.