'Beautiful' sisters Ruby and Shanzel Brewer remembered after Turners Marsh fire

A distraught father has shared his pain over the loss of his two young daughters who tragically died in a house fire as they slept.

Shanzel and Ruby Brewer, aged 10 and 13, were found dead on Sunday morning following a fire at a property in Turners Marsh, about 30 kilometres north of the Tasmanian city of Launceston.

Police and the Tasmania Fire Service were calls to the property on Austins Road about 3am on Sunday following reports that a shed was on fire. The bodies of the girls were found in the makeshift granny flat, where they had been sleeping in a bedroom with no smoke alarm inside.

Three other children had been sleeping in the main house and luckily survived the blaze.

The children's father Clifford Brewer took to Facebook on Sunday to remember his girls.

"To my babbie girl Shanzel Brewer, I love you with all my heart," he wrote on Facebook, sharing a photo of the 10-year-old.

"I with you were here with me and your sister Ruby Brewer. I will always love you two girls."

Mr Brewer said the girls were the best thing that ever happened to him.

Other friends and family shared their sympathies and mourned the loss of the two girls.

"Waking up to hear this tragic news and still can't believe my two beautiful little cousins have been taken away from us," cousin Kelsey Lee wrote on Sunday.

"You will forever be in my heart and I hope you both knew, that I love you dearly. Rest in peace Ruby and Shanzel."

Miraki Thompson wrote: "Ruby & Shanzel. I honestly don't know where to start I feel so numb! Rip I love you guys heaps will never forget all our good times.

"My heart is broken I feel so lost! no words can explain the pain! I'm speechless! I can't believe it ... It just doesn't feel real."

Another relative, Jason Wells, has created stickers to be sold to help raise money for the family.

"Please get behind this cause and help a Tassie family suffering the loss of their young girls lives tragically taken earlier this morning," he posted on Sunday.

A GoFundMe campaign has also been started to support the family.

Addressing media at the scene on Sunday Inspector John King said the family was distraught.

"The family are extremely distraught ... the father of the two little girls had initially called in the fire to emergency services," Inspector Kind said.

"Not only have the two little girls unfortunately perished in this fire, the three other children were in the main house."

Preliminary investigations suggest the fire may have been caused by a faulty electrical cord that provided power to the shed.

"An extension cord and an electrical heater in the flat are forming a major part of the investigation," Inspector King said.

The girls were enjoying a Queens Birthday weekend sleep-out at the time, the Hobart Mercury reports.

Police are preparing a report for the coroner.