The pair were apparently caught getting close at a recent polo event, where an eye witness reportedly saw them share a kiss under a blanket.
The Sun has claimed the prince and the 'Love Me Like You Do' singer - who have been friends for several years, after she performed at the Duke and Duchess Of Cambridge's wedding reception in 2011 - have gotten close after swapping texts in recent weeks.
After they met up at the Audi Polo Challenge at Coworth Park in Berks on 28 May, a source has now told the paper: "Harry and Ellie only had eyes for each other all night – they spent a lot of time sitting together under blankets.
They added that Harry has already been telling friends how much he likes Ellie.
She split from McFly bassist Dougie Poynter at the tail end of 2015, but recently admitted she could see them getting back together.
Asked about a possible reunion, she told The Sun: “Maybe. I hope so. We have something I know is special and I think other people see it – my friends see it, my family see it… but I think some things are just kind of unfinished, an unfinished story.”
Dougie also claimed he still loves Ellie, telling the paper in a separate interview: "We love each other very much, we're still best of friends. We hung out at Coachella, like all day, with her friends and my friends. It's really, really cool."
Prince Harry has previously had long-term relationships with Chelsy Davy and Cressida Bonas, and has also been linked to stars including The Saturdays' Mollie King, TV presenter Caroline Flack and 'Doctor Who' star Jenna Coleman.
Caroline recently opened up about her relationship with the prince in her autobiography, 'Storm In A C Cup', admitting: “To meet a prince is so unlikely it would be weird not to acknowledge it. However, once the story got out, that was it. We had to stop seeing each other.
“I was no longer Caroline Flack, TV presenter, I was Caroline Flack, Prince Harry’s bit of rough.”
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