Photo supplied.
Since September 5, several slips have occurred at the site about 6km south of Makarora, blocking one lane of the highway and prompting several overnight road closures to ensure motorists' safety.
Rain caused more material to come down on Wednesday.
New Zealand Transport Agency Central Otago area manager John Jarvis said the unstable area was about 100m above the road, where abseilers and helicopters equipped with monsoon buckets removed overhanging debris yesterday.
"It's going to take quite a few more weeks before we can actually leave the site. The priority is to keep at least a single lane open in a safe manner, albeit with a few delays, because it's a relatively low volume road but it's a very important link."
