ASB customers are reporting widespread issues with KiwiSaver, with balances showing up at zero.

One told RNZ he checked his KiwiSaver last night, only to find no money there.

"I check my KiwiSaver everyday, and last night the balance was at zero," Peter said.

He said he called the ASB fraud line, and was met with a pre-recorded message saying the bank was working to resolve the issue.

"I'm intrigued to know why, and I'd like to get an explanation from ASB."

ASB KiwiSaver balances appeared to have been restored this morning.

Peter said he had not received any communication from the bank about the issue, and found the whole thing "odd".

The same issue appeared across social media, with users saying they felt panicked and confused.

ASB has been approached for comment.