Steel reinforcing bar, or rebar, is widely used to strengthen concrete in houses, buildings and infrastructure.

Three companies have moved out of a Wellington high-rise where the steel reinforcing bar stretched in the Kaikōura earthquake.

The investigation excludes concrete reinforcing bar structures, steel bridge sections, pre-fabricated steel buildings and steel utility poles, among other products.

Seismic grade steel reinforcing bar that is not as strong as it should be has been sold in the New Zealand market.