Although the two stars kept mum on the reports, their pictures hinted that they frequently did spend most of their time together, reported Ace Showbiz.
In the movie franchise, Evanna, 23, and Robbie might not share the same scenes but they certainly feel comfortable in each other's company.
In the latest snap Evanna shared on Instagram, she and her rumoured boyfriend seemed very affectionate as the actress touched his chin and brought his face close to hers.
Evanna and Robbie, who seemingly have been together for a year, have even got their special nicknames, "Bug and Fuz."
When asked about the stars' romantic relationship, Robbie's representative refused to give any details.