Yao Wei Wu demonstrated what he says happened to him during an encounter with Vancouver police in January. (CBC)

The lawyer representing a Vancouver man beaten by police says the investigation of the incident was a farce.

Yao Wei Wu was beaten and injured on his doorstep at 2 a.m. on Jan. 21 after opening the door to police who were investigating a 911 call reporting a man assaulting a woman.

"He answered his door. He opened it when he saw the badge. He was pulled out, badly hurt and handcuffed," Wu's lawyer, Cameron Ward, said at a news conference Wednesday. "He was completely innocent."

Police later admitted the plainclothes officers mistook Wu, 44, for someone else.

The chief of police in suburban Delta, Jim Cessford, was asked by Vancouver police to conduct an investigation of the beating. In his report released Wednesday, Cessford found the officers were simply doing their duty and Wu was resisting arrest.

"This is absolutely a distortion of the facts," Wu said in a statement translated from his native Chinese. "The police version is completely false."

Ward called Cessford's conclusion "ridiculous."

"The whole investigative process, lasting more than nine months, was a farce," he said. He added that he was not surprised by the conclusion because whenever police investigate each other, allegations against officers are found to be unsubstantiated.

Wu, still recovering from his injuries, is suing both the Vancouver and Delta police departments.