The man who found abducted Chinese student Wanzhen Lu said the 22-year-old was confused and disoriented when he showed up on a quiet street in Ontario cottage country.

Lu had been missing for more than 72 hours when he reappeared in Gravenhurst, Ont., on Tuesday evening.

Police say he had been kidnapped Saturday evening while in the parking garage of his condo building in Markham, Ont.

Police said the international student was taken by four men in a violent abduction, who had seemingly been waiting for him in a stolen minivan. One of the men allegedly shocked Lu multiple times with a stun gun. A woman who was with Lu at the time was not harmed.

“Four suspects that were willing to go into that underground parking garage took Mr Lu with a significant amount of force, loaded him into a van and basically kept him, wherever they kept him, for more than 72 hours before finally releasing him,” Const. Pattenden said.

On Wednesday, investigators were searching for evidence in Gravenhurst.

The man who found Lu told CP24 that he did not want his name to be published because he feared for his safety.

“I did hear him say something about being kidnapped, so I rushed the dog in the house, grabbed my flashlight, went out to meet this lad,” he said.

“He told me he had been kidnapped, call the police, which I did immediately.”

He said he had been on the front lawn of his home with his dog Tuesday night when he heard a voice calling from the roadway.

The man said Lu was wearing a hoodie with tape on it and appeared to have marks on one wrist and one knee. Police believe Lu was dropped off on Doe Lake Road.

“He was pretty shook up,” the man said.

“He had no clue where he was and what had happened to him.”

Lu told the man that he had been handcuffed and had been brought to the area in a car.

He asked for a glass of water and drank it while waiting for police officers to arrive, which they did after about five minutes.

They took Lu to hospital, where he was treated for minor injuries, and then 150 kilometres south to the Markham area to talk to investigators.

The minivan believed to have been used in the kidnapping itself was found Sunday night in Toronto.

“We have obvious safety concerns here. We still have four suspects that are still outstanding,” York Regional Police Const. Andy Pattenden told reporters.

Police said they have not received any communication from the four men believed to be involved in Lu’s kidnapping at any point.

Pattenden encouraged them to contact lawyers and turn themselves in.

“We will figure this out – it’s just a matter of time,” he said.

The suspects are all believed to be men.

One has been described as 6’2” and heavyset with dark skin, and was seen wearing dark blue jeans and a dark blue jacket.

Another is said to be 6’1” with dark skin, and was seen in a black Canada Goose jacket.

Physical descriptions of the other two suspects are not available, but police have said that one was wearing a green-and-yellow hooded jacket and the other had on a black jacket, blue pants and a mask at the time of the kidnapping.

Lu, known by his neighours as a luxury car enthusiast, still has his Range Rover in his condo building’s underground garage. The Rolls Royce and Lamborghini that he also drives have been removed.

His parents are in Canada, visiting from China.

Lu, also known as Peter, is in the bachelor of business administration program at Yorkville University in Vaughan, Ont.

“Our investigators are going to keep an open mind to all possibilities,” said Const. Pattenden.

Police arrested a 35-year-old Toronto man Tuesday because they believed him to be connected to Lu’s disappearance, but later released him unconditionally -- meaning they had no evidence to support a criminal charge.