Is this video of a bear chasing a snowboarder a fake?

A video of a snowboarder being chased by a bear down the slope in Japan has divided internet opinion.

The footage, which seemingly shows Kelly Murphy completely unaware that a bear is running after her as she snowboards down a run in Hakuba, is already claimed by many to be a hoax.

Commenters on YouTube have queried whether brown bears live in Japan, while on Twitter a debate on the credibility of the clip is hotting up. User @georgewrussell tweeted, "Those who just cry fake are as annoying as the frauds," but @adamsich claimed that the bear splits in half for one frame, proving it's a hoax.

Here's proof that bear chasing a snowboarder video is fake. Bear splits in half for one frame. Other reasons too. pic.twitter.com/FoDk1LooAx

— Adam Sich (@adamsich) April 11, 2016

Ms Murphy told The Telegraph: "I'm here with my girlfriends but they were doing lessons and I went off by myself.

"I've been snowboarding since I was a kid so I felt safe.

"I didn't realise until I looked at the video today! I was freaking out when I saw it and showed my friends who told me to put it on YouTube.

"I've heard rumours that there can be bears, but that it is really, really rare!"

Kelly claims she didn't realise the bear was behind her because she was singing the Rihanna track Work - which is as good a reason as any not to notice being chased by a wild animal.

If the video is genuine it's terrifying, showing glimpses of the bear lumbering after Kelly at speed down the hill, with her only just managing to outpace it on a steeper section of the slope. If, however, it is a hoax, it's an impressive one, having convinced many viewers online.

This isn't the first time a video of an animal on the ski slope has raised questions of validity. Last season a video seemingly capturing a skier passing a mountain lion at the side of the slope triggered a similar debate, with some crying fake and others completely taken in.

Earlier this season, a video of a supposed "Yeti" caught on camera on the slopes of Spanish ski resort Formigal also caused controversy.