Selena Gomez and Zedd
Singer/actress Selena Gomez (L) and musician Zedd attend HBO's Official Golden Globe Awards After Party at The Beverly Hilton Hotel on 11 January, 2015 in Beverly Hills, CaliforniaGetty

Canadian singer/songwriter Justin Bieber is reportedly worried about former girlfriend, Selena Gomez's growing closeness with Russian-German music producer/DJ Zedd.

The 22-year-old former Disney star and the 25-year-old, whose real name is Anton Zaslavski, were photographed holding hands while heading to the Golden Globes afterparty.

Adding on, she also posed for photographers, resting her head on Zedd's shoulder.

"Justin is going to act like he doesn't care one bit, but in his inner circle, everyone knows he's hurting big time over the fact that Selena is with Zedd," a source told Hollywood Life.

"Zedd is a threat to Justin. He's super talented and successful. He's got a ton going on and he's just a nice guy, with an awesome sense of humor. Plus, he's sensitive and quirky and Selena likes that kind of stuff in a guy," the insider added.

Beiber and Gomez first began dating in 2010 but parted ways by the end of 2012.

During an interview with America's OK! magazine, Gomez credited her friends for helping her go through personal and professional challenges.

"I've learned a lot about myself and how I want to move forward with my life," she said. "I also took some time off to focus on the things that make me happy and the friends I need to help me stay grounded."