Tina Fontaine's body was found wrapped in a duvet cover purchased at Costco, Winnipeg police revealed Thursday.

Police have always said the 15-year-old's body was in a bag when it was pulled from the Red River near the Alexander Docks in Aug. 17, 2014.

Sgt. John O'Donovan, of the Winnipeg police homicide unit, told CBC News the information about the duvet cover was deliberately not released to the public.

"It was extremely frustrating for the family — there was very little that we could tell them because this was such an ongoing, tight investigation, so it was difficult for us to share with them what we were doing," O'Donovan said in an interview.

"It made me feel bad, not being able to tell Thelma Favel [Fontaine's great-aunt] and her family what we were doing and the extremes we were going to, and I certainly don't blame her for losing faith."

O'Donovan won't say who owned the duvet cover or whether it played any role in the arrest of Raymond Cormier.

The 53-year-old was arrested in Whistler, B.C., on Dec. 9 and brought back to Winnipeg, where he was charged with second-degree murder in Fontaine's death.

Officers tracked down close to 1,000 customers who bought the same duvet cover, but police didn't tell them exactly why they wanted to know about their purchases. O'Donovan said the customers went to great lengths to help out.

"People went to their cabins and took pictures of these things and sent them to us just to show that they had them. People went as far as India, Japan and the Philippines, where they sent them, and got pictures of them sent back just to show that yes I did have it and this is where it is now.

"It confirmed certain things to us which was useful," O'Donovan said. "If we hadn't done that, then basically we have another thousand people who have access to this item of clothing, to this item of bedding, so it had to be done."

Slaying renewed calls for MMIW inquiry

O'Donovan said it was September 2014 when police were able to identify a house in the eastern part of the city that Fontaine frequented.

At the time she went missing, Fontaine was in the care of the province's Child and Family Services. Her slaying sparked renewed calls for an investigation into missing and murdered indigenous women.

"We actually used some information that Tina had provided herself before her death, which was very helpful to us in establishing people that she was associating with and timeline, and that became very, very useful in our investigation right from the start," O'Donovan said, adding that a 911 call Fontaine had made in July 2014 to report a friend's truck stolen helped investigators.

Tina Fontaine

Fifteen-year-old Tina Fontaine's body was found in the Red River on Aug. 17, 2014, days after she had been reported missing. A 53-year-old man has been charged with second-degree murder in connection with her death. (Facebook)

"That helped, and just the people she had spoken to in the last hours and days of her life, basically."

O'Donovan said there were a number of suspects early in the case, including Cormier. But over time, investigators were able to eliminate all but one.

"It was definitely public help that brought us close to narrowing down our suspect pool," he said.

"We need that help, we need people, witnesses, people who will give us information. Something we can substantiate, and work on. Thing is, in every case somebody knows and they just need to come forward."

Police have also said that "covert" techniques were used, but O'Donovan said that was not information he could share yet.

Homicide outraged investigators

O'Donovan said the cost of the investigation is "not as much as that little girl's life was worth."

He said he remembers being asked to speak at the news conference that was held after Fontaine's body was identified. He said it was an emotional time for him.

"She's a child. This is a child that's been murdered. I think society, we would be horrified if we found a litter of kittens or pups in this condition. This is a child. Society should be horrified," O'Donovan told reporters at the time.

Sgt. John O'Donovan

In an interview with CBC News, Sgt. John O'Donovan of the Winnipeg Police Service's homicide unit revealed that the teen's body was wrapped in a duvet cover. (CBC)

When asked on Thursday about what he said back then, O'Donovan replied, "It was an outrageous thing to find this kid the way she was, and I know it outraged us as a unit working together.

"I felt I needed to say this and just get people's attention. It wasn't scripted, it wasn't prepared. It's just the way it came out."

O'Donovan said there have been 30 homicides in Winnipeg since Fontaine's body was discovered.

"All homicides are senseless, really. It's the most serious crime in the Criminal Code," O'Donovan said.

"Everybody who works in that unit, they believe in what they're doing and they put their heart and soul into it," he added.

"They all mean something to us, every one of them, but this one, because it was a child and because of the way that she was found — you know, we saw more of the pictures before she died, and it certainly hit home that this was not good."