NSW Police have reopened investigations into the 1990 disappearance and suspected murder of 16-year-old Colleen Walker-Craig, launching the first-ever search for her remains in the Nambucca River.

Colleen's mother, Gumbaynggirr woman Muriel 'Aunty Moonie' Craig, told National Indigenous Times the renewed search brought mixed emotions after decades of waiting.

"It is a surprise that they came up, but I am thankful," she said.

"But it's long overdue, I don't know how long it'll take for them when they [investigators] go away [to search] and how long it'll take for them to come back."

Colleen was one of three Aboriginal children killed over five months in Bowraville.

Her clothes were found weighted down in the river with stones but her body has never been recovered.

Three decades later officers from the NSW Homicide Squad and Marine Area Command have returned to the area to search across Bowraville and Macksville.

Aunty Moonie has spent her life trying to find answers.

"I would do anything to try to find out what happened to Colleen and where she is," she said.

"When Colleen went, a piece of our heart went too.

"We want her back so that we could heal."

The pain of losing Colleen has continued across generations.

"My kids, even though they're all big now, I can still feel their pain when I'm near them," she said.

"Thankfully I've got people like Taz and Leonie to help me push and that makes me feel better because now I can see that there's people willing to help me."

Aunty Moonie said her family has never been able to sit together and talk about Colleen's death.

"I don't think I've ever sat down with all the kids and talked about Colleen because she was a special part of our lives," she said.

"Maybe when we find her, we could all sit down and talk, and I'm hoping that that'll be soon because time's getting on."

She also criticised how police handled the case from the start.

"From the beginning they didn't do the right thing," she said.

"I think the only time they got frightened was when the other two kids went missing. That's when they rang me up to go and make a statement."

Aunty Moonie said she would continue fighting for justice for her daughter.

"All I can do is use my voice when I can or make noise, and that's what I've been doing," she said.

"I'm thankful for Facebook because now I've got a lot of people who help me share Colleen's story, and that's good."

More to come.