Niall Horan has hit out at a fan after she took a photo of him sleeping on a transatlantic flight.

The singer took to Twitter on Monday (August 1) to reveal his frustration after the devotee uploaded the picture online.

The fan said Horan wasn't feeling well and didn't want a selfie, but he was happy to speak to her.

The Irishman tweeted: "I think this sh*t is unreal.

"I mean if you can't sleep on a plane without people taking photos of you, what can u do."

The fan's original message read: "I sat directly next to Niall from One Direction for 9 hours on my flight home from London last night.

"He was sick and asked for no selfies, but here is a pic I snapped when he was sleeping lol he was so friendly!"

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