Doctors in Zhabei District Central Hospital said they were seeking help from police and a property company to work out what happened to a comatose patient.

Zhao Yaofa, a cleaner employed by Gonghe Mansion in Zhabei, was rushed to hospital after fainting in his employer's office yesterday morning.

The 53-year-old was allegedly assaulted by a property owner about 11 days ago after arguing over a trivial matter.

"He sustained a neck injury, but did not have a medical check in time as both sides agreed to settle the dispute privately. The attacker paid Zhao 500 yuan (US$60)," said a doctor surnamed Zhou.

Zhao told his employer yesterday morning that he felt sick. He fell to the ground suddenly before anyone on the scene could respond.

"He now lives on a respirator," Dr Zhou said.

The company said the male attacker had been told to report to Zhijiang Road W. Police Station for questioning.

 A police officer only said: "It was still questionable whether Zhao's condition was due to illness or if it was due to the attack."