WELLINGTON, Dec. 2 -- New Zealand opposition Tuesday called for government action to stem a spate of deadly road crashes involving foreign visitors after a young Chinese man was convicted of causing the death of his mother.

Shu Na Lo, 27, a Chinese student living in Australia, admitted in Christchurch District Court on Tuesday charges arising from the head-on crash in the South Island's Canterbury region.

He admitted careless driving causing the death of his mother, King Wai Yip, and injuries to his sister, May Wong Kot, and to 72- year-old Graham Dawson who was driving the car he struck head-on when his rental vehicle drifted across the road, The Press newspaper reported.

Defence counsel Miranda Rout told the court that Lo had possibly fallen asleep at the wheel although he had no memory of it.

She said the family was raising funds to fly their mother's ashes home for burial in China.

The Press reported that Police prosecutor Sergeant Paul Scott said Lo and his mother and sister had boarded a flight from Melbourne to Christchurch at midnight on Sept. 30 and had then hired a rental car to drive to South Canterbury.

The rental car crossed the centre-line and collided with another vehicle on the Fairlie-Geraldine highway about midday.

Lo's mother, who had been asleep in the back seat and not wearing a seatbelt, was thrown from the vehicle and killed.

His sister was the front seat passenger and received abdominal injuries. She was now in a wheelchair after spending a month in hospital.

Lo was disqualified from driving for 12 months on the charge of careless driving causing injury to Dawson, and has been ordered to pay 3,500 NZ dollars (2,753 U.S. dollars) emotional harm reparations.

He was convicted and discharged on the charges involving the death of his mother and the injuries to his sister.

Transport spokesman for the main opposition Labour Party, Phil Twyford, said after the case that the government needed to consider measures to reduce unnecessary deaths involving tourists.

"The government has downplayed the importance of crashes involving tourist drivers, but every one of these needless deaths is a tragedy for the families involved," Twyford said in a statement.

"Instead of ignoring these deaths the government must ask what it can do to prevent them."

Road safety campaigners have been calling for tourists to be tested before they can drive rental vehicles after a series of deadly crashes.