The new Police HR system is facing a budget blow-out of $8 million, but the Government says it's under control.

The system was supposed to cost $56.2 million, but has moved to $64 million. It was also supposed to be ready by April, but that's now September.

Labour MP Stuart Nash said it seems every time a Government Department or Crown entity puts in a major new computer system, it runs over time and over cost - something he finds unacceptable.

"If I was the Police Minister, I'd be hauling the Police Commissioner into my office and saying 'you must provide me a weekly update of what's going on here, because I'm most unhappy about this. This is not how it should be, and it's not what I signed off on.'"

But Police Minister Judith Collins said they've had assurances from the highest levels at PriceWaterhouseCoopers, that it will be ready by the new deadline.

"Police were unhappy with some of the testing results. The testing recently has been much better, and are much more confident that PriceWaterhouseCoopers can deliver."

Ms Collins said she can't give details because the contract is sensitive, but there are repercussions if the new deadline is missed.

"Quite clearly PriceWaterhouseCoopers has a lot on the line, and so I expect that they will in fact make sure that they actually complete this project."