Speaking on TV One's Breakfast show this morning, Miss Clark also said she believed police would look at the case again.
On Thursday, a High Court jury in Auckland found Chris Kahui not guilty of murdering his baby twins Cru and Chris two years ago.
"I feel that someone has to be brought to account," Miss Clark said.
"The two babies who were killed were treated so badly that they died and it's not right that no one is brought to justice for that."
She would not be drawn into criticising how police handled the case and the cultural sensitivity shown.
"It was an incredibly difficult investigation for them because a veil of silence came down over the entire family and everyone who knew them."
Miss Clark said police now had to decide how to go forward.
"The police are left thinking what do we do now? And while I understand in human terms the officer in charge of the investigation saying; 'that's it we've got nowhere else to go', I think you'll find that the police will sit down, they'll look at this, they'll sift back through the evidence they'll see whether there's any other angles."
