The two couples were holidaying in the country when the accident occurred at an intersection in Luggate township, near Wanaka on the South Island, on Thursday.

Cheung was airlifted by an Otago rescue helicopter to Dunedin Hospital.

He was reportedly in stable condition yesterday.

Photographs from the site show an articulated truck blocking State Highway 6, surrounded by emergency crews and their vehicles.

Nearby is the wreckage of the tourists' white rental car, crumpled and overturned from the impact of the crash.

After learning about the incident, Hong Kong's Immigration Department said it had contacted the Office of the Commissioner of China's Ministry of Foreign Affairs in Hong Kong, as well as the Chinese embassy in Christchurch for more details.

"We have been in contact with the family members of the victims and will offer assistance in accordance with their requests," a department spokesman said. He said the department would stay in touch with the victims' families and the authorities.

Yesterday, the Fire Services Department confirmed that the injured man is a retired fire officer but would not give further details.

It said the department's welfare unit had been in touch with the man's family and would provide any assistance necessary.

Cheung retired from the fire department about two years ago and his last post was deputy chief fire officer.

The two couples were part of a nine-person tour group travelling in two vehicles when the accident occurred at the intersection of State Highway 6 and State Highway 8A, south of Wanaka, on Thursday afternoon.

The driver of the truck, which was travelling from Wanaka towards Cromwell, was shaken by the accident but was uninjured.

New Zealand police did not comment on the circumstances of the crash.

It was unclear whether the car drove into the truck's path or if the truck was going too fast down Luggate Hill, local media reported.

A male cyclist was seriously injured in a collision with a taxi at the same intersection in August last year.