Officers discovered the 22-year-old's body after being called to the house at Main Street in the town of Ulverstone about 3am on Tuesday.

Detective Inspector Kim Steven said she had suffered knife wounds "consistent with being murdered".

She had been staying with a friend and her two children at the house after arriving from NSW two or three weeks ago, he said.

Police took a man into custody around 11am on Tuesday at a house some 200 metres down the street from the crime scene.

"There doesn't appear to be any known connection between the two people," Det Insp Steven told reporters.

The woman's friend had called triple zero in regards to a "prowler" being inside her house.

"The police had been on the phone to her for some 11 minutes, during that time uniform police have arrived. In that time they've located the deceased in another room of the house," Det Insp Steven said.

"(She's) obviously distraught, to witness something like that in your house. She's made a statement to us."

Forensic specialists, including some officers from Hobart, are examining the scene.

The street has been cordoned off and is expected to be closed for several hours.

Anyone who saw a vehicle, person or anything suspicious in the area at the time has been asked to contact police.

Australian Associated Press