Pop beauty Nicole Scherzinger has weighed in on Justin Bieber's concert delay, explaining that stars with young fans should always be on time.

Canadian superstar Bieber was slammed for his "disgusting" behaviour after turning up late on stage for the opening night of his 'Believe' tour in London on Monday (March 4).

Asked if she would have waited to see the 'Baby' heartthrob, Scherzinger explained to Digital Spy: "I mean if it were someone like Whitney Houston I'd be waiting! I'm getting too old to stay up late these days so I don't have a lot of patience for that kind of thing.

She added: "My team run this ship like a military. I run a tight, tight ship. When you've got a lot of young fans like I do, it's important to be on time. Especially if they have school the next day!"

Bieber took to Twitter to apologise for his lateness, but denied reports he delayed the show by two hours: "since i have been here it hasnt been easy with the press at times but I have loved it. so let me say this... last night i was scheduled after 3 opening acts to go on stage at 935 not 830 but because of some technical issues i got on at 10:10..so... i was 40 min late to stage. there is no excuse for that and I apologize for anyone we upset. However it was great show and Im proud of that (sic)."