A representative for Patrick Schwarzenegger has shut down speculation the actor was caught taking drugs at the Coachella music festival in California.

Arnold Schwarzenegger's 22-year-old son was among the celebrities who headed to Indio over the weekend (15-17Apr16) to party at the star-studded event, where headlining acts included the reunited Guns N' Roses, LCD Soundsystem and Calvin Harris.

However, Patrick raised eyebrows after he was photographed popping a pill at the three-day bash, prompting speculation about the mystery substance.

His representative has since spoken out to insist the pill was nothing illegal, revealing he was caught on camera taking herbal supplement Party Smart, which aims to reduce the severity of hangovers after drinking booze.

"He doesn't take drugs," his publicist added to Entertainment Tonight.

Patrick has yet to comment on the incident, but Miley Cyrus' ex-boyfriend did take a moment during his Coachella trip to share a photo of himself with celebrity chef Guy Fieri.

In the snap, the youngster is featured sticking his tongue out, with a drink in hand, as he poses beside Fieri.

"Had to ask for a photo," he captioned the picture.

Other celebrities who were spotted partying during the first weekend of Coachella included Rihanna, Leonardo DiCaprio, Jared Leto, Nina Dobrev, Aaron Paul, Lorde, and Taylor Swift, who was front and center as she cheered on her boyfriend, DJ Calvin Harris, during his big set on Sunday (17Apr16). He was joined onstage by Rihanna, who surprised fans with a performance of their 2011 smash We Found Love, while he also brought out Big Sean for their song Open Wide, and British singer/songwriter John Newman for their track Blame.