Niall Horan and Barbara Palvin are rumoured to be dating again.

The One Direction star is a fan of Australian pop-rock band 5 Seconds of Summer and supported them by attending their gig at Shepherd's Bush Empire in London last night.

Fans spotted him hanging out at the side of the stage near the Hungarian model, who was also at the gig. The pair have been linked to since late last year.

Last month reports of a breakup surfaced, but it seemed like a different story when 20-year-old Barbara posted a view of the stage on her Instagram account, confirming she was at the gig.

"was so happy to see @5SOS perform tonight! finally!! (sic)" she captioned the shot.

It seemed the pretty brunette was aware of the uproar her post could cause, as she quickly followed it up with a tweet.

"about my last post. i tagged @5SOS on instagram... cant deal w what its sayin on twitter. sorry.. just hope u dont creat drama. (sic)," she wrote on her Twitter profile.

It was claimed the pair's busy schedule was to blame for their romance falling apart.

However, a source did confirm they were still friends.

“There was no big fall out, things just fizzled out as Niall and Barbara are both working in different parts of the world,” an insider previously explained.

“They are both really busy and Niall is focused on recovering and getting ready for the band’s massive Where We Are Tour."

Barbara has previously addressed their relationship, insisting they are just friends.

"Niall is a nice guy, we just hang out. We're mates," she told OK! Online at the ELLE Style Awards this year.

"I'll always hang out with boys. I'm a tomboy; I played football when I was younger."