Street art is one of the few areas of collecting where artworks liberated from public spaces can be sold for a huge profit in private auctions. And Banksy is at the centre of it.

The big question is, who owns street art?

Join us as we take a look at five examples where works by Banksy have been "stolen".

5. Umbrella Girl

In February 2014, two men attempting to remove Banksy's Umbrella Girl mural from a wall in New Orleans were accosted by local residents and left hurriedly as the police were called.

After the attempt, the work was covered up with a mural. A similar fate befell the artist's iconic Balloon Girl in London, which was covered up with boards for well over a decade after the paint began to peel away.

The massive rise in the value of Banksy's work, which now sells for millions, has led to a thriving market for pieces that are removed from their locations - either by the owners of the property or others.  

4. Everything but the Kitchen Sphinx

During Banksy's recent residency in New York, a huge number of the pieces he produced were defaced.

Additionally, a replica of the Sphinx, made from cinderblocks and titled Everything but the Kitchen Sphinx, was placed in a waste lot in Queens.

It was stolen almost immediately.

A group of men began selling bricks from the sculpture for up to $100 each before loading it into a van and driving off with it.

Its whereabouts remain unknown.

3. Mobile Lovers

The story behind this most recent example is a little complicated. Essentially the piece was shown on Banksy's website shortly before it was discovered in his native Bristol, UK.

The ownership of Mobile Lovers is contested - Image: Banksy

It was removed from the wall by the leader of a local youth club, who claimed he had commandeered it for safekeeping.

Shortly after making that statement, he announced the work would be sold at auction to benefit the club.

The council weighed in, stating that as the painting was discovered on council property it belonged to them, and it was summarily removed from the premises and taken to Bristol Museum, where it will stand on public display until the question of ownership is resolved.

2. Slave Labour

This piece was painted on the side of a London shop in 2012, but went missing in 2013.

It resurfaced at a Miami-based auction house in 2013 to widespread protests from London residents, who believed the work had been created as a gift to the community.

The painting was withdrawn from a Miami auction in 2013, but sold in London later in the year - Image: Fine Art Auctions Miami

It was swiftly withdrawn from the sale but soon reappeared in London, where it was sold by the Sincura Group for £750,000 ($1.1m).

The owners of the shop stated they were glad to see the back of it as they had been subject to demands for protection money from local gangs, who had threatened to damage the work.

1. Stealing Banksy auction

The Sincura Group will host the largest sale of the artist's work ever held, in an April 27th-ending auction provocatively titled "Stealing Banksy?"

The collection includes some of the most iconic works from across the artist's career, all of which were removed from their original locations.

The sale will include No Ball Games, taken from a wall in Tottenham. It will be auctioned for charity with a £1m ($1.6m) estimate.

Banksy's No Ball Games will headline the controversial sale - Image: Sincura Group

Others include the giant Liverpool Rat, estimated at £225,000 ($378,517), and Girl with Balloon, which is valued at £400,000 ($672,920).

The company stated that there was no intimation of criminal activity and that the majority of the pieces were consigned by the owners of the land on which they were painted - who often face problems with constant public attention and issues with reselling their property due to the buildings acquiring listed status.

Ultimately it's a complex area. Each time that Banksy produces a new work controversy flares up as various groups scrabble for ownership - a situation he presumably finds hilarious.