Kourtney Kardashian ‘furious’ after son Reign, 10, addresses rumour Justin Bieber is his real father

Kourtney Kardashian was reportedly left furious after her son, Reign Disick, addressed a very wild rumour that he is Justin Bieber's son.

The California youngster is the third child of mum Kourtney Kardashian and her former long-term partner Scott Disick.

The couple split in 2015, shortly after Reign's birth, following nine years of on-again-off-again romance.

Kourtney, 45, and Scott, 41, are also parents to 15-year-old son Mason and daughter Penelope, 12.

Of course, there's never ever been any suggestion that Reign's father is anybody but Scott's, however, in recent weeks, some conspiracy theorists have claimed that Reign's appearance seemingly mirrors that of Bieber, with some bizarrely demanding a paternity test on the child.

And while you mightn't expect such an outlandish rumour to reach the ears of the stars it involves, Reign recently addressed it during an Instagram Live.

On Monday (31 March), Reign sat with Alabama Barker - the daughter of Kourtney's husband, Travis Barker - and her boyfriend, Scooter Jackson, where he insisted he has no relation to Bieber.

"Bro, I swear," he allegedly began during the live video, as per E! News. "Justin Bieber’s not my dad."

Reign went on to explain: "I think Justin Bieber was 16 when I got born." Though it's worth noting the singer was actually 20.

"Yeah, I don’t think my mom would do that," he added.

Reign spoke about the rumour (Robino Salvatore/GC Images)

Kourtney reportedly thinks the conspiracy is 'ridiculous', with a source telling US Weekly: “Kourtney doesn’t give any heed to the reports that Justin is Reign’s father.

“She thinks it’s ridiculous and laughs that people online would even believe that.”

Meanwhile, another source added to the Daily Mail: "Kourtney has never talked to Reign about the rumors and she would imagine this was the first time he had ever heard them.

“Kourtney was livid. She told him that there are so many silly rumors about the family and that he is not to believe anything. She tries to keep her kids away from this stuff but as they get older she is unable to as easily.”

The speculation comes shortly after Kourtney was forced to address rumours about her other son, Mason Disick, after it was alleged that he had become a father.

“I rarely address rumors or conspiracies regarding myself or my family,” the reality TV star wrote on her Instagram Story.

“But this is about my child and it feels wrong to let anyone think for a second that these lies are remotely true.”

Kourtney Kardashian released a statement (Instagram/@kourtneykardash)

Kourtney continued: “They are not. Mason does not have a child. These accounts that pretend to be him are definitely not.

“They are FAKE.”

She added: “My son really values his privacy, and I am asking all media to please be respectful: he is a kid with feelings and a beautiful life ahead of him. Please stop spreading false narratives and spinning lies.”

Tyla has reached out to Kourtney's reps for comment.