York Regional Police say a ransom demand was made in the case of Wanzhen Lu, a Chinese international student who was abducted by a group of masked men in a Markham, Ont., parking garage on March 23.

Lu was found suffering from minor injuries in Gravenhurst, Ont., three days later

Police wouldn't confirm any details of how or when the ransom demand was received, or the amount sought, but Const. Andy Pattenden did tell CBC that it was "made late into the investigation."

"We cannot provide further details as it's now evidence before the courts," he said via text.

One of four suspects wanted in connection with the abduction turned himself in to police this week.

A Canada-wide warrant was issued Monday for Abdullahi Adan, 37, of Toronto, who was wanted on four charges: kidnapping, forcible confinement, assault with a weapon and assault.

Adan turned himself in overnight, York Regional Police Const. Andy Pattenden confirmed to CBC Toronto early Tuesday.

Abdullahi Adan, 37, of Toronto, is one of four suspects in the abduction of a Chinese international student north of Toronto on Mar. 23. (York Regional Police)

"It's definitely just due to the ongoing pressure, I'm sure, from the public, from the media, from social media, as well as our investigators who are working diligently to find all the suspects," Pattenden said in a telephone interview.

Adan appeared in court via video link in Newmarket, about 50 kilometres north of Toronto, Tuesday morning. His case was put over to Friday.

Lu owned condo, drove luxury cars

Police have yet to reveal details about why Lu may have been targeted.

The CBC has confirmed that he owned a unit in that Markham condominium building where he was forced into a van.

Records show he purchased the unit outright in 2018.

Police had also previously confirmed that Lu drove several luxury cars, and on Tuesday, CBC confirmed that there are liens against him in connection to four vehicles: a Ferrari 488 GTB, a Lamborghini Huracan, a Rolls Royce Wraith and a Land Rover Range Rover Velar, which documents show he was leasing.

Photographs from an Instagram account, since deleted, appear to show Lu with the same cars. He has also been photographed in what appears to be high-end designer clothing.

Police are not confirming that an Instagram page, picturing three vehicles matching the description of those connected to Lu, belonged to him. They have also warned of the possibility of false accounts purporting to be his. (Instagram)

Lu, a Chinese national, is enrolled in a bachelor of business administration program at Yorkville University, a private institution with locations in Toronto, New Brunswick and British Columbia.

Pattenden said investigators are "working closely" with the Lu family, who flew in from China after Lu was reported missing.

He would not offer specific details on their whereabouts, because "there are still concerns for their security as we have three suspects still outstanding."

3 suspects still sought

Adan was the first suspect to be named after surveillance cameras recorded three masked men taking Lu, 22, from the parking garage of a condominium building in Markham, around 6 p.m. ET on March 23.

Police have said the men forced Lu into a black Dodge Caravan after shocking him with a conductive energy weapon, while a fourth was driving the vehicle.

On March 26, Lu was found alive after knocking on the door of a home in Gravenhurst, Ont., almost 200 kilometres away from where he was taken.

He was suffering from minor injuries and was taken to hospital. Police say he has since been reunited with his family.

Police are advising the remaining suspects to seek legal counsel and turn themselves in. Police are also asking members of the public to contact them if they have any information about the investigation.

The suspects are all described as male. One suspect is described as wearing a mask with blue pants and a jacket. The second has dark skin, is six feet one inch tall and was wearing a black Canada Goose jacket. The third was wearing a green and yellow jacket with a hood.