Justin Timberlake performs during the BRIT Awards, celebrating British pop music, at the O2 Arena in London February 20, 2013. REUTERS/Dylan Martinez

Justin Timberlake has defended his expletive-filled London show last week, insisting the crowd was "age appropriate" and his swearing was "all in good fun".

The singer performed at the BRIT Awards in the British capital on Wednesday night, before heading over to The Forum venue in nearby Kentish Town for his own special gig.

The former 'NSYNC star debuted a more grown-up look and peppered his set with curse words, but Timberlake insists he didn't mean to offend gig-goers with his bad language.

When asked about his cursing during an interview with Britain's Capital FM, the star explains, "I swore a lot, every club show we do is age appropriate... I'm 32 years old, sweetheart. Nobody's going to tell me anything... It's all in good fun. This is my analogy, it's like dressing for the weather. If you are going to play at The Forum, it's a proper rock 'n' roll venue...

"I'm not a rock 'n' roll star but we're gonna put on my version of a rock 'n' roll show. And it's 18 (years) and up."