0716 GMT June 22, 2021
The work, outside a beauty salon, shows a girl hula-hooping with a bicycle tire. It went up next to a bicycle that is missing its back wheel.
Amid speculation over whether the piece was a Banksy, a screen was fitted to it. In an ironic twist, soon afterward the screen was sprayed with graffiti, BBC wrote.
A picture of the work was posted on Banksy's Instagram on Saturday morning.
He began spray-painting trains and walls in his home city of Bristol in the 1990s, and before long was leaving his artistic mark all over the world.
Banksy is famed for poking fun at big companies and sending political messages through his work.
The salon the artwork appeared outside is on the junction of Rothesay Avenue and Ilkeston Road in Lenton, a popular residential area for students.
A spokeswoman for Banksy told the BBC she did not have any information on it.
It comes as the city remains the highest in the country for coronavirus infection rates, with some speculating Banksy could have chosen Nottingham for that reason.
Others wondered whether the bike was a nod to the city's famous Raleigh factory.
A shop owner described seeing the artwork unfold when a van "with blacked out windows" pulled up at about 17:00 BST on Tuesday.
Alex Mitchell, 31, said: "I only saw the driver. I didn't know what was going on or whether I should call the police.
"He pretended like he had broken down but he was there for at least two hours."
Mitchell said at one point the man came in and bought two Ribenas.
He said a piece of cardboard was left "gaffa taped to the wall" and when he returned the next day, the same person was there again.
"I asked him 'who is the artist' and he just winked at me," he said.
"I'm not going to say whether it is Banksy or not, it definitely looks like one but no-one saw who painted it.
"Maybe he was just passing through."
Surinder Kaur, who owns the salon the artwork has appeared on but does not own the building, said she had never heard of Banksy.
She said: "I just saw people taking photos of the side of the shop and thought 'what's that about?'
"I'm shocked and excited. It's such a nice painting and if it is a Banksy - wow!"
Josinya Powell, 39, said: "Nottingham needs something like this right now - something to talk about rather than coronavirus.
"If it is Banksy that'd be amazing – I'd say to him 'thanks babes'."
Amanda Forest, 49, said: "With Nottingham being in the headlines because of COVID it's something to put a smile on your face.
"Even if you're not interested in art, everyone knows Banksy."
Banksy expert Paul Gough, from Arts University Bournemouth, said he had his doubts as to whether this was the real deal.
"The quality of the drawing in the hands and the feet isn't as accomplished as I've seen in other works," he said.
"And it's not as topical. The last four or five pieces Banksy's done have been really addressing the crisis we're in at the moment with wit and humor."
In July, a Banksy artwork encouraging people to wear face masks appeared on a Tube train in London.
And in September, Art Attack presenter Neil Buchanan dismissed rumors Banksy was his secret alias.
Nottingham City Council said the artwork has "attracted interest and excitement", "Banksy or not".
It put a temporary plastic covering over the work to protect it, but urged people not to congregate around the piece due to coronavirus restrictions.
Shortly after the transparent film had been placed over the artwork, it was vandalized.