The cabby, Kung, was arrested after an online video showed the taxi hit what appeared to be a bull on the Lung Yeuk Tau section of Sha Tau Kok Road on the way to Sheung Shui.

The video, believed to be dashcam footage from the taxi, showed the cow crashing into the front of the taxi. The animal staggered few meters and rolled on the road.

It managed to stand up and slowly left the road after the accident, and a male voice could be heard saying "wow, that's a cow" after the accident.

A cattle concern group said on Facebook on Monday that the animal was treated at a farm , but its condition was bad, and believed it had walked for a while before being found by Agriculture, Fisheries and Conservation Department staff hours later.

Officers said yesterday that the animal died, and its body had been taken away for an autopsy.

Kung did not report the matter to the police, who launched a probe after the video was put online.

"The police puts high emphasis on the case, and it is being followed up by the Traffic New Territories north headquarters," the police said.

Kung was arrested yesterday on four charges, including dangerous driving, interfering with a vehicle involved in an accident to conceal evidence, and failing to stop and report after an accident. He was still being detained as of last night.

The maximum penalty for dangerous driving is three-year imprisonment and a fine of HK$25,000.

"First offenders are disqualified from driving for at least six months; for a second conviction, a person is disqualified for at least two years," the police said.

Anger seethed online about Kung.

One commented: "How come the driver can't see the big cow, please disqualify yourself from driving and don't bring trouble to people."

Another said: "The driver is not even stepping on the brake even though a big cow is standing there, will he do the same if the one standing there is human?"