Rita Ora claims her relationship with Calvin Harris went ''weird'' after she released 'I Will Never Let You Down'.

The couple dated for a just over a year before separating in June 2014 and she claims cracks started to appear in the romance in the wake of the success of the single - which Calvin wrote and produced - which came out in March the same year.

Rita wonders whether things went sour between her and the superstar DJ - who is now dating Taylor Swift - because they mixed ''business'' with pleasure.

Discussing went wrong between the pop pair, Rita told the new issue of Britain's Marie Claire magazine: ''There was a reason why I split up with him ... It was more of a thing where I was in awe. I was at that point in my relationship where I felt he could do no wrong. I thought he had my back and that he'd never steer me wrong. But then 'I Will Never Let You Down' came out, and everything started to go a bit weird. I don't know if it was because business was mixed with personal or what.''

The split was acrimonious at the time, with Calvin preventing Rita from performing 'I Will Never Let You Down' at the Teen Choice Awards.

However, the 24-year-old beauty has no regrets about the end of their relationship, because she believes there's a reason for everything that happens in life.

She added: ''There's a reason why I'm at this point in my life where I feel like I have so much musical freedom, and I don't have to explain myself to anybody.''

Rita also confessed she is scared of being on her own and prefers to be in a relationship even though love often makes her feel ''crazy''.

She even compares the feeling to needing a drug.

Rita - who has also dated Rob Kardashian and Ricky Hill - shared: ''I'm afraid of being alone. I'm not afraid to admit that, you know. I'm not embarrassed to admit that. I just hope it's not a never-ending cycle. Sometimes love just makes you feel crazy. And that feeling that we have as girls, just to have that feeling, even for five seconds, it's like crack. I mean, don't compare it to that, but you know what I mean. It's like comfort eating.''

Rita's full interview is in the July issue of Marie Claire magazine, which is out on June 23.