Harry Styles is furious about Zayn Malik and Louis Tomlinson's "stupid and reckless" behaviour.
The One Direction hunk's bandmates were captured on film joking about smoking marijuana as they passed around a suspicious-looking roll-up cigarette as they were reportedly being taken to Peru's Estadio Nacional in Lima on April 27, and Harry is said to be unimpressed by their antics, which were reportedly filmed on Louis' phone.
A source told The Sun newspaper: "Harry is annoyed about the whole debacle. This should be one of the biggest weeks of the band's career with the launch of their UK stadium tour.
"Instead it has been taken over by this controversy. Harry thinks it was a stupid and reckless thing for Louis to allow to be filmed in the first place."
The footage emerged yesterday while the group are in the midst of the UK leg of their 'Where We Are Tour' and the remaining members of One Direction - Harry, Niall Horan and Liam Payne - were not present in the short clip.
Harry has distanced himself from their behaviour and has even been travelling separately to his bandmates since he isn't "into these antics".
The insider added: "Despite Harry's reputation, he's incredibly professional and mature, and not into these sorts of antics."
Meanwhile, Louis seems worried and is anticipating the "reaction" from fans.
The source said: "He was up checking his phone to see the reaction.
"He understands the whole world is talking and he is trying to work out how to limit the damage."
The boys are set to take on North America from August 1 and there are now concerns about whether the authorities will allow them into the country because of the alleged drug use.
The insider added: "Everything is about America. It would be a disaster if Zayn and Louis had problems. The authorities could make an example of them."