Scooter Braun, the music mogul who made headlines for a long-running dispute over Taylor Swift’s master recordings, has reportedly been left by two of his biggest clients.

According to Billboard, both Ariana Grande and Demi Lovato have parted ways with the manager.

Colombian star J Balvin, who signed with Braun in 2019, left in May and is now managed by Roc Nation.

But reports that Justin Bieber has also split from Braun have been denied.

Braun is one of the world’s most successful music managers, with clients including David Guetta, Black Eyed Peas, Ava Max, Carly Rae Jepsen and Quavo, according to his website.

He started his career as a teenager, promoting parties and events in Atlanta, before being signed to Def Jam Records.

But his big break came in 2008, when he spotted a 12-year-old Bieber singing on YouTube and saw star potential.

He tracked the youngster down through his school, asking board members to put him in touch with Bieber’s mum, and signed him to a record label he had formed with R&B star Usher.

Bieber quickly became one of pop’s biggest stars, and Braun has steered his career through several ups-and-downs, including a period in 2013-14 where the singer faced a string of arrests for vandalism, dangerous driving and assault.

“I was not going to give up on him, I was not going to let him die,” Braun told the Guardian in 2016.

He eventually helped the singer rehabilitate his image by arranging a Comedy Central “roast” that showcased his humility, paired with a stretch of singles including Sorry and Love Yourself that marked his transformation from teen idol to adult star.

Ariana Grande signed with Braun in 2013, since when she has released six albums, all but one of which topped the US Billboard charts.

After the Manchester bombing, which claimed the lives of 22 of her fans, Braun organised the One Love benefit concert that helped raise millions of pounds to support the families of the victims.

Grande has not released an album since 2020’s Positions, and is currently working on the movie adaptation of the Broadway musical Wicked.

It is unclear whether she is severing all ties with Braun outside of management.

Demi Lovato started working with Braun in 2019, saying at the time: “Dreams came true for me. I officially have a NEW MANAGER. And not just any manager but the one and only Scooter Braun.”

An unnamed source told Variety that their split was amicable. Indeed, on Sunday, Braun posted a birthday message to Lovato on his Instagram story, calling her “one of the kindest souls out there”.

The manager is probably best known for his feud with Taylor Swift, which began in 2019 when he bought her former record label Big Machine for $300 million (£227m) through his investment group Ithaca Holdings.

That meant he gained control of the master recordings of Swift’s first six albums, which she saw as an act of aggression that “stripped me of my life’s work”.

Her animosity appears to have been partly fuelled by Braun’s relationship with Kanye West, who he managed for two-and-a-half years from 2015.

The rapper had constantly sought to belittle Swift, first by interrupting her acceptance speech at the 2009 MTV Awards, then by recording a song where he took credit for her fame, and later by putting a waxwork sculpture of her naked body into one of his music videos.

Swift felt Braun had encouraged and endorsed this behaviour; and exacerbated the hurt by posing for a photograph with West and Bieber that was posted to Instagram with the caption “What up Taylor?”

In response, she blocked requests for her music to be used in TV shows and films – cutting off a vital source of income for Braun’s investment group. She then started re-recording all of her old material, reclaiming ownership of the albums and further devaluing the originals.

Braun later sold the star’s catalogue to another investment firm, Shamrock Holdings. A year later, he sold Ithaca Holdings to South Korean entertainment giant HYBE, which represents acts like BTS and NewJeans.

Braun is now HYBE America’s CEO and earlier this year helped the company purchase US hip-hop label Quality Control, whose acts include Quavo, Lil Baby, Lil Yachty and City Girls.