A building expert says some in the building sector are stockpiling supplies, including timber.
Julian Leys from the Building Industry Federation says there are shortages of supplies across the sector, but Carter Holt Harvey's decision to stop supplying some major retailers adds further panic for builders.
The Commerce Commission says it will look into Carter Holt Harvey's decision to halt timber supply to some retailers, while continuing to supply large customers.
Leys spoke to Corin Dann.
