Jacinda Ardern asks Minister of Justice to look at prisoners' custody rights

Prime Minister Jacinda Ardern has spoken to the Minister of Justice about which rights prisoners are entitled to, after the family of a Waikato woman murdered by her partner were forced to fight for custody of their children.

Kim Richmond was murdered by her partner Cory Jefferies in 2016. Jefferies was the father of her three children. 

After her murder, Richmond's parents took temporary custody of their three grandchildren.

As soon as the guilty verdict came in, Richmond's parents applied to be the children's legal guardians. But, from behind bars, Jefferies repeatedly delayed the custody process.

It took eight months to be granted full custody - and Jefferies can still challenge it.

Ardern said on Tuesday she intends to look into the flaws in the system which allowed such a case to happen.

"I was looking at some of the detail last night about this story, and what really struck me is that you might have a completely different set of circumstances, for instance, had the mother survived and had a protection order," she told The AM Show.

"So it seems like we might have an anomaly there with someone, who had a protection order, having a different set of outcomes and engagement with the other biological parent versus if they have lost their life to violence."

Ardern says it seems to be "an area that warrants looking at".

"I spoke to the Minister of Justice last night to talk that through because it does seem to be an area that warrants looking at because there will be other cases like this," she said.

"I don't think anyone would feel comfortable with what has happened in this case to this family, so he is going to go away and have a look at that issue."