The body of a man, who suffered shotgun wounds to the head, was found in the hall of a large detached property in the village of Anstey, Leicestershire, shortly before 1am yesterday.
A woman, who suffered gunshot wounds to her chest, was taken to the Leicester Royal Infirmary where she died shortly after arrival.
A second woman also suffered gunshot injuries and she was taken to the same hospital where her condition was "stable". She is said by officers to be too ill to be interviewed.
Detective Inspector Roger Skene said the dead and injured were all aged in their late 30s to early 40s and were "closely connected" to each other.
DI Skene said: "We are still trying to establish exactly what happened and we have launched a murder investigation. The person detained in hospital has not been arrested and is not a suspect at this stage." Officers are trying to trace relatives of the dead.
A weapon was found at the scene and was being examined by forensic scientists.Reuse content