A call for the government to apologise to all victims of abuse in state care.

LISTEN ABOVE: Indigenous Rights Commissioner Karen Johansen spoke to Rachel Smalley

The Human Rights Commission's penned an open letter to the government to start an independent inquiry into state care abuses from the 1950s to the 1990s.

There've been individual apologies and compensations for past claims - but the extent of the abuse is unknown.

Indigenous Rights Commissioner Karen Johansen signed the letter and said it's been prompted by growing concerns amongst her colleagues and herself.

She told Rachel Smalley a confidential listening panel made a recommendation in June last year for an independent inquiry but that's been rejected.

"And we think that it's time for us to call on all New Zealanders to ask the Government to initiate a comprehensive inquiry."

Ms Johansen said no one's looked at the systemic reasons why the abuse happened and what's more they haven't looked at how this might never happen again.

A foster care abuse survivor, Daryl Brougham said after his case was investigated by the government, it became clear an apology is needed.

"When you're sitting there being hit and you're thinking why are these people doing this, there's only one outcome I could think of and that's I want you to say sorry and you need to say sorry."

More than a 100,000 kiwis were taken from families and put in state care from the 1950s to the 1990s, where many suffered serious physical, sexual and emotional abuse.

Mr Brougham said the way the government's dealing with it now is too slow.

"I know of people who are still under the historical claims process and they've been waiting for 10 years. I also know of some who have passed on and their investigation hasn't even been looked at."

The government's been compensating and listening to state care abuse survivors since 2001, but last year rejected a recommendation to carry out a full inquiry.

Daryl Brougham said it's not an unreasonable suggestion from the commission.

"I would like to see an inquiry but a much shorter process. They've got the knowledge, they've got the information. They've been doing the historical claims process for a while now."