A sumo champion has been fined for hitting a junior wrestler with a karaoke machine remote control.

Former grand champion Harumafuji Kohei, 33, was ordered to pay 500,000 yen (€3,675) for assaulting rising star Takanoiwa Yoshimori, 27, while drinking at a bar in Tottori city.

Takanoiwa's skull was initially thought to be fractured by the karaoke remote and he had to withdraw from a tournament as he was hospitalised for three days.

However, doctors later revealed his injuries were not so severe and there were no symptoms of skull fracture or brain fluid leakage.

The incident, which occurred in November while the two Mongolians were on tour with other wrestlers, has threatened to taint the image of Japan's national sport.

Harumafuji began slapping and hitting the younger wrestler with the remote control for checking his phone.

He had already been told off for his bad attitude by grand champion Hakuho Sho, the Japan Sumo Association crisis management committee found.

Harumafuji was forced to resign in late November over the incident.

Last week, when he was found guilty of assault, his lawyer released a statement on his behalf.

"Because of this incident, my life as Harumafuji is now set to be sharply different from what I thought it would be.

"I have a feeling of chagrin, to be honest. But the responsibility is all mine."

Harumafuji began his professional sumo career in 2001 and reached the top makuuchi division in 2004 before being promoted to sumo's highest rank of yokozuna in 2012.

At 133kg Harumafuji was the lightest man in the top division in 2015 and was noted for his technical skill.