A four-year-old boy was disqualified from a children's bike race in China after kicking a fellow competitor off his bike in an apparent act of cheating.

Footage shows the boy in red deliberately targeting a rival dressed in white in Chongqing on July 14, during a kids' race held on a makeshift track inside a gym.

After an initial failed attempt to knock the child off his bike, he lands a well-aimed kick that sends the competitor crashing to the ground.

The crowd gasps in shock as the child in white, reportedly injured and bleeding, picks himself up and bravely continues the race.

However, an irate parent runs onto the track, halts the race, and scolds the boy in red for his behaviour.

Organisers later disqualified the child, and his parents were made to apologise and bow before the injured child's family.

They also reportedly agreed to cover medical expenses, but later cut off contact, prompting the victim's family to post the footage online in the following days.

Local reports claimed the boy in red had been encouraged by his coach to interfere with opponents.

During a training session the day before, the boy had fallen after allegedly failing to block a competitor's path, prompting the coach to tell him to 'treat others as they treat you', instead of discouraging unsportsmanlike conduct.