The discovery of a possible hazardous substance in a building in central Wellington has prompted its evacuation.

The 14-storey Lambton House, which houses Vodafone, Education New Zealand and Victoria University's continuing education centre, was cleared of staff on Monday afternoon after the find.

Vodafone said a technician working in the lift well in the property at 160 Lambton Quay identified a substance as being potentially hazardous and the building was cleared by building management as a precaution.

It said samples of the substance were being tested and until it was known what it was the building will remain closed.