EXCLUSIVESamantha Murphy missing: Husband pictured smiling outside police station

The husband of missing mum-of-three Samantha Murphy has been spotted speaking with police officers on Friday morning.

Ms Murphy, 51, left her home on Eureka Street in East Ballarat, north-west of Melbourne, to go for a run in Woowookarung Regional Park just after 7am on Sunday.

No trace of her has been found since, and it's understood homicide detectives have been called in to help with the search as it enters its sixth day.

Mr Murphy smiled after meeting with detectives at Buninyong Police Station on Friday.

Michael Murphy, the husband of missing mum Samantha Murphy has been pictured leaving Buninyong Police Station

He spent just an hour inside the station before leaving with an officer, who escorted him to his car

He spent just an hour inside the station before leaving with an officer, who escorted him to his car.

Mr Murphy appeared casual as a waiting media pack photographed him.

The station is being used by emergency services units as the headquarters for its ongoing search for Ms Murphy.

Victoria Police Inspector Bob Heaney said detectives were relying on information coming from the public to help track down Ms Murphy's whereabouts.

Police struggle to find missing mother Samantha Murphy