The Prime Minister says updating our antiquated adoption laws is on the agenda - but it will take some time.

Broadcaster Toni Street is putting the issue in the spotlight, raising difficulties she's having legally adopting her biological son she had via surrogacy.

She told Mike Hosking that she and her husband have had to fill in lots of paperwork and be interviewed multiple times.

Street says Oranga Tamiriki and the Family Court should not be involved when it comes to biological surrogacy. 

Jacinda Ardern is saying she agrees the more than 50-year-old legislation needs a significant redraft.

She says it's on the to do list, but there can't be a quick fix.

"It was 10 years ago now that the Law Commission did work on this, and that needs to be updated. I have spoken about to Minister Little, it is on his work programme, but it is a piece of law that will take a bit of work."