Hundreds of lambs are on the loose in the Marlborough Sounds after a stock truck crashed earlier this week.

Photo: 123rf

Marlborough Roads journey manager Steve Murrin said the crash happened on Kenepuru Road near Willow Bay on Tuesday afternoon.

Mr Murrin said while the driver of the truck was not injured, around 400 lambs escaped from the vehicle.

The lambs were now wandering in the dense bush in the area, and a team of musterers would attempt to round them up today, he said.

"Kenepuru Road is quite a windy road in the Marlborough Sounds, we had a stock truck tip its trailer over ... onboard that trailer was about 400 lambs which are now running loose in the native bush," he said.

"There was a couple of [lamb] casualties I believe at the site but most of them have got free."

Mr Murrin said the public were advised to be careful driving in the area and wandering stock signs were in place.

He said the road was usually pretty quiet, but it would be getting busier over the next few days as there were a lot of holiday homes in the area.