A Kent YouTube prankster who helped stage a fake art heist that caused a stampede at the National Portrait Gallery was jailed today.

Daniel Jarvis, 27, of Gravesend, and other "Trollstation" pranksters caused a mass panic during the hoax on July 5 last year - coming just a week after the Tunisian beach massacre.

Magistrates warned such "warped" stunts could cause fatalities in the panic.

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Visitors at the National Portrait Gallery in Trafalgar Square fled and some were trampled while one woman passed out.

The group then moved on to Tate Britain, where they carried out a fake robbery and kidnapping.

They later uploaded the videos to their YouTube channel, which has more than 700,000 subscribers and has had more than two million views.

Today Jarvis, 27, Endrit Ferizolli, 20, Ebenezer Menzah, 29, and Helder Gomes, 23, were jailed for a total of 72 weeks, after pleading guilty to two counts of using threatening behaviour, causing fear of unlawful violence.

During the art hoax, the group carried fake paintings in, while Ferizolli carried a speaker in and played a loud siren.

The other three members then pulled tights over their heads, picked up the paintings and ran through the gallery, shouting "I've got the painting", while another member, Danh Van Le, filmed them.

VIDEO: CCTV footage shows the panic caused by fake art heist

Prosecutor Katie Weiss told City of London Magistrates' Court: "There was panic in the gallery and a stampede of people leaving the gallery.

"One of the complainants was so stunned by what happened, she said she was absolutely terrified.

"They ran out of the gallery. They looked as if they have stolen art.

"One of the males shouts, 'this is a hoax'."

A statement from Barry Palmer, head of security and and safety at the gallery, was also read out.

The hoax took place a year after a shooting at a Jewish museum in Belgium, he said, "and just over a week since the mass shooting in Tunisia".

He added: "Incidents such as this have the potential to call into question our ability."

The group then moved to the Tate Britain gallery in Millbank, central London to carry out a similar stunt.

They carried in the fake paintings, put tights over their heads and then ran out again waving the pictures, and dragged out a female accomplice.

Ms Weiss said: "They ran around as if they were committing a robbery.

"Mr Gomes grabs the female by the neck. The defendants come out and go downstairs, with the female in a headlock.

"We have a witness who said he was very distressed."

Passing sentence, District Judge Mike Snow said Trollstation was a "a group that believes it is amusing to film acts impacting on members of the public and then upload those mages o to the internet".

He said: "As you know, Sunday is a busy day for art galleries, with many tourists and families.

"I was told that the defendants believed what they were doing was funny. Their sense of humour is warped.

"It was quite foreseeable those attending the gallery, not being in on the joke, but being familiar with recent scenes of people running for their lives from terrorist acts, would be terrified and panic. And that is what happened.

"A stampede followed at the National Portrait Gallery. Some people were trampled on. Later, a similar visitor was found unconscious.

"The aggravating features in this case are the high levels of fear of violence that were experienced, the risk of death or serious injury in the stampede.

"The offences took place in art galleries whee vulnerable persons are likely to be present. There was a high level of planning. It was a group action.

"And it was an action which involved the public humiliation of the victims of the behaviour, by recording their terrified reactions to upload on to the internet."

Jarvis was locked up for 20 weeks, Menzah, of Peckham, south east London, was given 18 weeks, and Gomes, of Stockwell, south London, was jailed for 18 weeks.

Ferizolli, of Colindale, north London was given 16 weeks in a young offenders' institution.

Van Le, who filmed the stunts, was jailed in March this year for nine months for a bomb hoax.

As he left the dock film student Jarvis, wearing a white t-shirt and grey tracksuit trousers, gave a thumbs up and a peace sign to supporters in the public gallery.

The others showed no emotion as the sentences were passed.

Jarvis and Gomes had previous convictions for

invading the pitch at a football match between Tottenham Hotspur and Partizan Belgrade

in November 2014 and trying to take photos with players, the court heard.

Gomes also had a conviction for carrying out a fake "break up" on Valentine's Day last year, when he approached a stranger in a coffee shop and tried to break up with her.

He pulled out a box and threw underwear and a sex toy on the floor, before sniffing the underwear and telling the victim "I used to love this smell".

The video was later posted on YouTube and Twitter and the victim was humiliated, the court heard.