Police fears for the safety of a Malaysian tourist missing in the Southern Alps have risen.

Kok Wong, 32, was last seen at a youth hostel in Aoraki Mount Cook Village on Wednesday afternoon.

He is lightly clad and has now spent two nights in the open in cold conditions.

A search team of 26 people would keep searching this afternoon, incident controller Senior Constable Brent Swanson, of Lake Tekapo police, said.

"We now have grave concerns for his safety," he told NZPA.

A helicopter scoured the area yesterday and a civilian dog handler searched yesterday and this morning, but neither found any trace of Mr Wong, Mr Swanson said.

Mr Wong had indicated he wanted to visit the Red Tarns Track and The Hooker Valley.

He failed to show up for his bus at 10am yesterday and his bag and other personal items were found in his room.

He was due to fly from Christchurch bound for Melbourne at 1.45pm today.

Police said they were making efforts to contact his family in Malaysia.

They appealed to anyone with information about Mr Wong to contact them.