Pop superstar Justin Bieber lashed out at a photographer as he lost his temper in the latest drama during his UK tour - just hours after a health scare forced him to leave the stage.

The 19-year-old Canadian singer burst out of a vehicle and lunged at the man but was restrained by minders in an incident which was captured by a film cameraman.

He had been hustled into a vehicle by his team after leaving his central London hotel - but he then burst from the van, swearing and making threatening comments.

"What did you say? What did you say?" he shouted, before swearing as his heavies dragged him back in the vehicle.

The footage has been posted on the Channel 5 News website, after a week which has seen him castigated for letting down fans, then being treated by medics after struggling for breath on stage.

Bieber described his frustration and said he "let the paps get the best of me", adding that his adrenaline was high with a series of messages on Twitter.

"Trying to feel better for this show tonight but let the paps get the best of me," he wrote.

"Sometimes when people are shoving cameras in your face all day and yelling the worst thing possible at you - well, I'm human. Rough week.

"Not gonna let them get the best of me again. Gonna get focused on this show tonight. Adrenaline is high now. Gonna put it on the stage.

"Only way someone can break you is if you let them," he added.

Charles Murray, a cameraman for 5 News witnessed the incident and said it was "an angry outburst".

He went on: "He deliberately went out of his way to shove the photographer. The photographer shouted back at him as Bieber got into his car.

"Bieber then decided to get back out of the car and slapped his camera out of the way."

The star, wearing a red top and beanie hat, was heard to shout: "I'll beat the f*** out of you."

The Canadian singer is due to perform another show at the O2 Arena tonight in a week he would probably prefer to forget.

Last night he quit the stage mid-song complaining of shortness of breath and was checked over by medics.

Bieber left the stage mid-song during his O2 concert after complaining of being "light of breath".

The teen sensation was performing in front of thousands of fans on the third night of the London leg of his world-wide tour when he fell ill.

His manager Scooter Braun said he was seen by a doctor backstage at the venue who told him not to return to the stage.

However, fans reported that he did make it back to the spotlight to finish his Believe show.

In a video posted by a fan on YouTube, Bieber's manager Scooter Braun tells the audience: "Justin got very light of breath, the whole show he's been complaining. He's backstage with the EMTs (emergency medical team) and the doctor.

"They're telling him they want him to go and see somebody and find out what's going on with his lungs, he's just told me that in five minutes, if it's OK with you guys, he's going to come out and finish the show.

"So he might not be jumping around as much and everything else, you guys need to be patient with us, we're not trying to be disrespectful, we're not trying to get you guys home late, we're truly trying to put on a show for the people who love him."

The manager had previously tweeted his joy that Bieber started the show 10 minutes early.

One fan tweeted: "Biebers not well and has gone off stage!

"He literally was so out of breath on stage in the middle of beauty and a beat and then went off!"

She later added: "Aww @justinbieber came back in stage after the doctors told him not to and he was incredible #believe #inspiration."

Bieber then published a picture of himself in a hospital bed after being checked by doctors for breathing problems.

The singer, who uploaded the pictures to his Instagram account, also thanked fans for supporting him while he "figures out" what happened.

He said: "Getting better. thanks for everyone pulling me thru tonight. best fans in the world. figuring out what happened. thanks for the love."

But fans raised questions over the timing of his illness, claiming it is a publicity stunt to win back their affection after he was slammed for his late appearance on Monday night.

On fan claimed on Twitter: "Justin Bieber was not sick, its a Publicity Stunt to make up for his late show."

While another speculated: "Justin Bieber publicity stunt collapse because he cocked up the other night by being 2 hrs late for his fans. Anything for sympathy?"

The singer was heavily criticised by fans and parents of young children for starting his concert late on Monday night.

Many were reduced to tears when forced to leave the venue just minutes into his performance, which started shortly after 10pm, in order to catch trains homes.

Bieber later apologised and blamed the delay on technical difficulties.