The teenager who avoided a prison sentence after pulling out a huge zombie knife on a busy Croydon street may yet spend time behind bars.

Joshua Gardner was 17 when he smashed the terrifying weapon into the side of a car as the driver cowered inside.

A video of the shocking attack, which took place on London Road in May, went viral and shows Gardner smashing the passenger window, causing the driver to jump out of the car and run off.

There was outrage when a judge decided the attack, which was in broad daylight, didn't warrant any time in prison.

And London mayor Sadiq Khan even asked for the suspended two-year prison sentence to be reassessed.

He has got his wish as the Solicitor General has now referred the original sentence to the Court of Appeal.

This means there is a chance his sentence could be increased, although it may stay the same.

The Solicitor General Robert Buckland said: “After carefully considering the details of this case, I decided to refer the sentence to the Court of Appeal due to the serious nature of the offence concerned.

“Gardner took to the streets in broad daylight, terrorising his victim and those members of the public who witnessed this extreme act of violence with a dangerous weapon.

“It is now for the court to decide whether to increase the sentence.”

What was his punishment?

Joshua Gardner hit the front window six times with the knife as the driver sat inside

Gardner, of London Road in Thornton Heath, was sentenced at the Old Bailey on November 27.

He had previously pleaded guilty to affray and being in possession of an offensive weapon.

At the hearing, Judge Anuja Dhir sentenced Gardner to two years in prison but crucially this sentence was suspended for two years.

In other words, he won’t be sent to prison unless he misbehaves again in the next two years.

As part of the sentence, Gardener was told to undertake 150 hours of unpaid work and abide by a curfew which stops him leaving his home between 7pm and 7am for nine months.

What did he do?

Joshua Gardner chased after the car and kicked one of the rear passenger doors

In the footage Gardner is seen cycling along the road and stops next to a blue VW, which is stationary on London Road.

The 19-year-old driver of the car pulls out from a queue of traffic and appears to almost hit Gardner, forcing him to jump out of the way.

The VW then hits an oncoming vehicle.

Gardner drops his bike to the floor and runs after the car, pulling out the huge zombie knife as he does.

He kicks the rear passenger door behind the driver and then swings the knife six times against the driver's front window in an effort to smash it.

Gardner then attempts to get into the vehicle via one of the passenger doors, but finds it is locked, so he runs around to the other side of the car and goes out of view of the camera.

The driver desperately tries to drive away, with the windscreen wipers moving up and down, and Gardner then appears in view of the camera again as he kicks the front passenger door at least twice.

Another two men are seen running towards the car as Gardner smashes the front passenger window with the knife.

At this point the driver gets out of the car and runs off.

Luckily the driver was not injured and returned to his vehicle after Gardner made off.

Defendant 'kidnapped at gunpoint and forced to sell drugs'

Joshua Gardner appeared to almost get knocked off his bike as the driver moved out of traffic

Judge Dhir said the contents of a pre-sentence report and probation report played an important role in the sentence.

In the probation report, the judge revealed that between March 26 and April 2 this year, Gardner was kidnapped at gunpoint by a gang over a friend’s drug debt, before being forced to sell drugs to pay off the debt.

According to the judge, he was “bundled into a car” and “threatened with a gun” because of the debt which one of his friends had run up.

He was kept against his will for 10 days, and made to sell drugs to work off the debt.

The court heard that some of that information has been corroborated by police, who have described the account as “credible and accurate”.

In the report, the probation officer points to the kidnapping as a reason Gardner had been carrying the huge zombie knife at the time of the attack on the car.