Louis Tomlinson has outed himself as the unnamed passenger to declined photos on Robbie Williams' flight.

In April, Take That star Robbie shared an Instagram post in which he said that cabin crew had asked him for selfies during a flight. He also revealed that one crew member had told him that he was "much nicer" than another celebrity on board who had refused to take photos.

"That made me bristle. I know that other celebrity - and he's a lovely lad," Robbie wrote at the time, without naming the star. "Who knows what was going on in his world that day?"

In a new interview with Rolling Stone, former One Direction star Louis said he believed he was the unnamed celebrity. He explained that he had been grieving at the time.

"Robbie never actually called me out on it, but I'm sure I was who he was talking about," Louis said, before explaining why this kind of incident has made him more cautious. "I was right in the middle of my grief."

He added, "I felt cross with the world, to be honest."

The 33-year-old described the experience as a "tough" situation.

"What's tough in that situation, psychologically, is that you know there's no answer other than 'Sorry, I'm a c**t,'" he told the publication. "Because you know there's no excuse you can make that can kind of alleviate that blow."

Louis added that instead of a photo, he had offered to sign something for the crew member, but said that "people are less excited about signatures these days because they can't put them online like a photo."

Reflecting on the experience, Louis said that interactions like this could "end up putting you off leaving the house next time, because you just think, 'All I was doing there was trying to protect myself.'"

However, the singer added that he always tries to "push through" these feelings, sharing that the "best way of staying mentally healthy is actually letting the world in".