Police in Dubai have arrested a man whose YouTube film alerted them to an alleged attack by an Emirati man on an expatriate driver.

The case has sparked a debate over strict national laws on filming public scenes and people.

Using its twitter feed, Dubai police announced on Wednesday officers had "arrested the man who shot the video of the bus driver incident."

Police were only alerted to the attack after the son of the alleged attacker complained that the video, uploaded to YouTube, damaged his father's reputation.

The video was removed but subsequently reloaded on July 15.

It shows a man native to the emirate slapping and beating an Indian expatriate van driver with his igal, or headband, on July 13.

Dubai police told local media that they had also earlier arrested an Emirati man for the attack.

Responding to a question on social media from an Australian expatriate in the UAE over the law, the police said the cameraman was arrested "because he shared" the video.

In a later clarification, the feed said: "You can tape it and deliver it to the police. You shall not share it over social networks ... If a crime was video recorded, the recorded material has to go privately to the police and not shared over Internet."

According to local newspaper Gulf News, the cameraman happened to be passing by when the fracas erupted.

The report added that Major General Al Mazeina said the case will be transferred to the public prosecutor.

The Emirati man's son allegedly complained to police that his father's reputation has been damaged since the video was uploaded on to the internet and seen by hundreds of thousands of viewers.