The Government says the earthquake-damaged AMI Stadium in Christchurch will need to be assessed before any decision can be made about holding games there.
New Zealand's second-biggest city is set to host five pool games and two quarter-finals during the tournament which begins in May.
Rugby World Cup Minister Murray McCully says there are serious liquefaction problems at the ground and some structural problems with the stadium following February's quake.
The final decision will rest with the International Rugby Board, he says.
The Government is waiting for engineers' reports before making decisions on whether games scheduled to be played there in September can go ahead.