The Government may have to help cover the costs of the broken Interislander ferries, Transport Minister Gerry Brownlee says.
The Stena Alegra, which is a temporary replacement ferry for the Aratere, is out of action with a hole in its hull after it ran into a Wellington wharf in strong winds on Tuesday.
KiwiRail is investigating how the crash happened and said it was too early to say how much the repair would cost.
The Stena Alegra was brought in to replace the Aratere after it lost a propellor during a Cook Strait crossing on 5 November last year.
The Aratere was due back in on the water this week after being repaired in Singapore but its return has been delayed by the discovery of new cracks.
Mr Brownlee said an investigation into Tuesday's Stena Alegra crash was still under way, so the full cost had not yet been determined.
However, it was quite possible KiwiRail could have to ask the Government for additional funding due to the problems, he said.
"We're talking through all that, but the fixed numbers are not available at the moment.
"We'll find out in the next couple of days exactly what the reason was. I was told it was extreme weather but it was raining yesterday - hardly extreme."
Mr Brownlee told Morning Report the Stena Alegra is safe.
He said it had performed well since it got to New Zealand and he was happy with the way KiwiRail was handling its repair, and the repairs to the Aratere.
Shambles says Peters
New Zealand First leader Winston Peters said the trouble with the ferries had been a long-running fiasco and an absolute shambles.
"You've got passengers, you've got freight and the most the important transport connection we've got, and the minister doesn't know what's going on and never will by the sound of it," he said.
KiwiRail chief executive Peter Reidy said the issues were unacceptable and that it would turn them around.
In the meantime, it was trying to work out what happened and whether the captain took the right course of action.
"We have quite sophisticated video information that tells us all about the weather, the speed, we can track the options that he took and we'll assess that when we get the information," Mr Reidy said.
Cook Strait crossings for the Stena Alegra have been cancelled until at least Sunday but KiwiRail said its services would be back to normal for the busy Easter holidays starting next week.