Justin Bieber wraps up his final show in London without major hitches on Friday, a day after collapsing on stage after suffering from shortness of breath and hours after being involved in a verbal altercation with a photographer.

 LONDON, ENGLAND, UNITED KINGDOM (MARCH 8, 2013) (REUTERS) -  Pop star Justin Bieber wrapped up his final London show without a hitch on Friday (March 8) after a week riddled with paparazzi run-ins and a trip to the hospital.

The Canadian-born singer was treated by doctors backstage and given oxygen on the third night of his London shows. He returned to the stage after a 20-minute break and completed his set but was later taken to hospital as a precaution, the singer's representatives told Reuters.

"He was a lot more better. He was really good yesterday but he improved a lot more today. Yes, it was amazing, absolutely amazing," said 18-year-old Danielle Welch, who attended both Thursday and Friday's concerts.

The singer also had an altercation with a UK photographer on Friday, caught on camera by Reuters, which showed Bieber getting out of a van, trying to move towards the unnamed photographer and threatening him.

He was reacting to the man's foul-mouthed criticism of him and his security team after the singer appeared to have made contact with the photographer as they moved towards the vehicle.

The bouncers held Bieber back, but the incident has already created more negative headlines for one of the world's biggest pop stars.

Some fans said the singer's action was understandable.

"I think it was their (photographers') fault. Everybody needs their privacy," said 10-year-old Evan Clark.

"If you're having that (being filmed) every minute of everyday, potentially it's going to get to you at some stage or another, doesn't matter how good you are in front of the camera," said Paul Barnett, who was at the concert with his wife Sarah and 6-year-old daughter Laura.

"I think his kind of very clean-cut image is perhaps marred a little bit now after this tour, but I guess he's growing up and these things happen, don't they?" said Sarah.

Since being discovered on YouTube in 2008, Bieber has built a huge following of mainly teenage girls attracted to his clean-cut image, slick videos and catchy pop songs.

But the intense media spotlight that follows him around the world has clearly unnerved the "Boyfriend" singer.

Bieber has had several run-ins with paparazzi in recent years and took to Twitter this week to criticise the media for what he called fabricated stories about him during his stay in London, where he was performing his sold-out tour.