Rita Ora was seen getting "really cosy" with Scottish DJ Calvin Harris over the weekend.

The chart-topping producer - who has collaborated with the likes of Rihanna, Florence Welch and Kylie Minogue - recently split from Victoria’s Secret model Anne V.

According to sources, Calvin has since moved on and is enjoying a flirty relationship with songstress Rita.

The pair were spotted at Las Vegas nightclub Hakkasan on Saturday night, where Calvin regularly DJs.

An onlooker told the New York Post that Rita “was in the DJ booth during his entire performance and the two were seen getting really cosy and kissing.”

Sources added to the US publication that Calvin and Anne V. "split amicably".

Rita on the other hand, had a very public war of words with ex flame Rob Kardashian.

The reality TV star took to Twitter at the end of last year to claim Rita was unfaithful a number of times.

"She cheated on me with nearly 20 dudes while we were together, I wonder how many she will sleep with now that we're apart. But I mean 20?!!!" he exclaimed on the social networking site.

"How can a woman who is so busy trying to start her own career have time to be with so many dudes all while in a relationship?! I'm actually disgusted a woman could give up her body to more than 20 in less than a year's time while trying to start a career (sic)."

Rita slammed Rob's decision to air his feelings so publicly earlier this year.

"I don't vocalise things that don't deserve attention. But it was something that was so unnecessary. Why would you flood people's brains with unnecessary sh*t? In my world, things like that just aren't important. Twitter...can ruin your life. I thought I nearly had a 'ruined' moment, but no," she said.

"When you're involved with someone for a while and they decided to express their feelings to the public - that's not my personal way of therapy, but I guess everyone takes split-ups differently. You should have to sit an exam before you go on Twitter to see if you're mentally stable."