Heavy rain has postponed the re-opening of State Highway Six between the Gates of Haast Bridge and Haast Pass summit.
The Transport Agency now says the road will not be open again until Wednesday at the earliest.
The highway - the only link between the West Coast and Otago - has been closed since a slip on Wednesday.
West Coast manager Mark Pinner sais heavy overnight rain destabilised the slip site again and brought new debris down on the road, making it unsafe for contractors to continue work.
He expects a report on the problem later in the day, but the additional debris means the job has got bigger.