The Mount Gambier man accused of murdering 55-year-old Mount Gambier woman Rachel Moresi has been extradited to Mount Gambier.

Troy Earle James, 53, appeared in the Warrnambool Magistrates Court this afternoon with the presiding magistrate extraditing his return to the Mount Gambier Police Station in the custody of Detective Sergeant Nathan Murray.

The defendant was refused bail and remanded in custody.

Just after 1pm on Wednesday, police were called to a home on Pick Avenue after a person was seen collapsed at the property.

When police first arrived, they noticed a toxic smell coming from within the premises and requested Metropolitan Fire Service to attend and make an assessment.

Once the property was safe to enter, police discovered Ms Moresi deceased inside.

Detectives from Major Crime Investigation Branch and Forensic Response officers attended the scene on Wednesday night and yesterday morning to assist local police.