Launceston Detectives have questioned three people over the brutal murder of a couple in Ravenswood.

The bodies of 31 year old Angela Maree Hallam and 21 year old Joshua Eric Newman were found with multiple stab wounds at the Pioneer Parade address on Wednesday night after firies extinguished a blaze at the Housing Tasmania property.

While details are still scarce - Detective Inspector Scott Flude suspects their deaths were motivated by a relationship issue. No charges have yet been laid.

An autopsy has confirmed the two died from extensive blood loss as a result of the stabbing.

The murder weapon hasn't been found.