UPDATED 9.31pm Police have named the woman found dead on on Main Rakaia Road in rural Canterbury Road on Sunday night.

She was 22-year old Renee Larissa Duckmanton of Christchurch.

Detective Inspector Darryl Sweeney said Ms Duckmanton was a sex worker in Christchurch and they're "working to ascertain whether or not that forms part of the investigation and circumstances surrounding her death."

Police said she was involved in the sex industry and they're working to try to find out whether that has any connection to her death.

Investigators have ruled out a link between a series of fires and Ms Duckmanton's death.

They said they're working round the clock and making progress in the inquiry, but haven't released the results of a post mortem carried out today.

MORE: Scene investigations continue after Selwyn body found

Detective Inspector Darryl Sweeney said she died an "unlawful death" and had been burned, but was unable to give any further details as to the cause of her death.

Police are now appealing for sightings of Renee Duckmanton over the weekend.

Rakaia Rd has been reopened this evening.

Police are expected to release more information about the woman's death at a media briefing tonight. 

Ms Duckmanton's body was found on Main Rakaia Rd, 500m from State Highway 1, by a member of the public driving past about 7.40pm on Sunday.

Police initially said the death could be connected to a series of suspicious fires in the Selwyn area that night, but they've now ruled out that link.

"As a result of a number of inquiries, police currently have nothing to suggest that the fires lit along the Selwyn River are linked to the death of a woman who was found on Main Rakaia Rd.

"Police have now launched a separate investigation into the cause of these fires."

Ms Duckmanton lived with her mum Tracy at the Kowhai Terrace house in the Christchurch suburb of St Martins which was cordoned off by police last night.

Her father Brent McGrath was too upset to talk today but did say that he was "very, very devastated" at the loss of his "adorable" daughter.

The family was given the terrible news from police at around 10.30pm yesterday.

A close family member described the woman as being "really bubbly, really happy, a lovely girl".

"We are all devastated. It doesn't feel real," she said. 

"We're a pretty small family.

"She was pretty much a kid herself. Even though she was 22, she was still young.

"She messaged me in April but I haven't properly seen her since last year. We'd catch up at family gatherings and we had our own lives.

"It's made me realise that things can change in a heartbeat and you need to make time to see your friends and family."

Ms McGrath said police have been slow to release information to them.

"We are just getting information when we read it on the news really," she said.

"The police aren't saying much but I think they are on to something. I hope so."

She said Ms Duckmanton, who had no children, "wasn't perfect".

But she was horrified to learn that she had been killed.

"We definitely want justice served. We really do, no matter who did it."

It is the second tragedy to strike the McGrath family in two decades.

Mr McGrath lost his parents, who also raised her, in a double death 20 years ago.

"It's something that Brent never got over. And now this. It's awful."

Jason Manuel, 47, who lives across the street said they are "good people, a normal family".

Mr Sweeney said: "Police are grateful of the Rakaia community’s patience and assistance as police go about their investigation.

"We appreciate the closing of the Main Rakaia Road has caused some disruption, but would like to thank them for their understanding during this time."