The National Inquiry into Missing and Murdered Indigenous Women and Girls is losing two more staffers.

Susan Vella, the commission's lead lawyer, has left "effective immediately," according to a note from chief commissioner Marion Buller on the commission's website on Saturday.

The inquiry will also lose Aimeé Craft, the director of research, who will return to her job at the University of Ottawa on Nov. 1.

Buller said she was "disappointed" to learn Craft decided to return the university's faculty of law.

A communications advisor with the inquiry told CBC News by email that no one from the inquiry was available to speak Saturday night.

MMIWG chief commissioner Marion Buller said she was 'disappointed' to learn Craft decided to return the University of Ottawa's faculty of law. (Darryl Dyck/Canadian Press )

In Buller's note, she said the commissioners and current staff members remain committed to meeting a mandate given by the Liberal government.

"We are bound together through the powerful testimonies of family members and survivors who have already shared their stories with us in Smithers, B.C., last week and in Whitehorse, Yukon, this past spring."

The inquiry has already lost several key employees since it launched, including former executive director Michèle Moreau, who announced she was stepping down in June following the departure of three other key staffers that month.

Marilyn Poitras, an inquiry commissioner, left suddenly in July.

Calls for Buller to resign

News of the departures did not sit well with Sheila North Wilson, grand chief of Manitoba Keewatinowi Okimakanak.

"It's telling, again, the state of crisis that this national inquiry is in," North Wilson told CBC Saturday night.

North Wilson renewed a previous call she's made for Buller to step down.

Sheila North Wilson, grand chief of Manitoba Keewatinowi Okimakanak (MKO), says the chief commissioner of the inquiry needs to resign. (CBC)

"She needs to find somewhere in her heart to do that because it's not about her, it's about families."

North Wilson said the tone of the controversial long-awaited inquiry has been set by Buller, which has led to serious problems on the file.

She said families with missing and murdered loved ones are fed up and some want a complete reset on the inquiry.

'I'm starting to lose my faith'

"I'm getting very stressed and I'm starting to lose my faith every day," said Sue Caribou, a Cree grandmother who sits on the inquiry's family advisory circle.

Caribou waited years for the inquiry. Several members of her family have been killed and she's still searching for answers about two loved ones who are missing.

Sue Caribou speaks at an emotional news conference in this photo taken in Winnipeg. (Michael Fazio/CBC)

One of whom is Tanya Nepinak, who disappeared in 2011 in downtown Winnipeg. Police charged Shawn Lamb with her death, but her body has never been found.

Caribou said it's getting hard not to lose hope about the inquiry and is trying to stay optimistic about the answers it could bring for families.

"I'm praying," she said.

The inquiry wrapped up hearings in B.C. last week and will head to Winnipeg with a community hearing set for Oct. 16.

From there, it will continue across the country making stops in Saskatoon, Halifax, Edmonton, Yellowknife, Quebec and Nunavut.

The RCMP pegged the number of missing and murdered Indigenous women in Canada at just under 1,200 in a 2014 report, but many — including members of the current Liberal government — believe that number is flawed and may actually be as high as 4,000.