Te Anau police want car rental companies to put "reminder notices" in their cars for overseas drivers, after another tourist was killed in a crash near Milford Sound on Saturday.

A 61-year-old Israeli woman died and two others were taken to Southland Hospital after their rented Toyota Corolla left the road and crashed into a tree just south of Knobs Flat on the Te Anau-Milford Rd about 12.10pm.

Senior Sergeant Cynthia Fairley said the dead woman was a rear-seat passenger.

One of the occupants had serious injuries and the other moderate injuries.

They were both in a stable condition and were expected to be in hospital for most of the week, Ms Fairley said.

It was not clear who the driver was.

The vehicle's front right corner was extensively damaged.

The weather at the time was fine and clear.

The crash, which had been attended by fire, police, ambulance, as well as the serious crash unit, was still being investigated.

She said anyone who saw the incident or who might have information about it should contact Invercargill or Te Anau police.

While the cause of the crash was still not known, it highlighted the need for overseas drivers to be educated about New Zealand roads and driving conditions, Ms Fairley said.

It was believed the group were in the South Island on a mini tour and had been walking the Milford Track, she said.

Driver education in the area was "pretty good" and included arrows on the road to remind drivers of the correct direction of travel and, while this had made a difference, more could still be done, she said.

Ms Fairley said she planned to speak with car rental companies about putting a reminder notice at the front of the vehicle with basic tips such as the importance of sticking to the speed limit, wearing seatbelts and not passing on double yellow lines.

"But it's very hard to educate people on roads and conditions - especially for [conditions] like torrential rain, if they're not used to it."

A staff member at Apex Car Rentals at Queenstown Airport said road safety information was included in the rental contract and was also in larger writing on a handout, in the rental agreement folder. gwyneth.hyndman@stl.co.nz

- © Fairfax NZ News