Police have confirmed a woman was sexually assaulted over the weekend when a couple were "disturbed" in their bedroom.
The incident happened about 3am on Sunday at a Gladstone Rd property in Richmond, near Nelson.
Detective Senior Sergeant Craig Johnston said officers were concentrating on finding the offender.
"It is of great concern to us that the person who committed this crime is out in our community and I would encourage anyone with information that may be relevant to this investigation to come forward," he said.
Police have increased patrols in the area and are asking people to keep themselves safe by looking doors and windows and keeping vehicles secure.