Police are warning anyone heading into the bush in Whanganui's Ruatiti to stay alert - as they hunt for a man wanted for double homicide

Police say 29-year-old Mitchell Cole is being sought in relation to the deaths of two people found at a rural property in Ruatiti over a week ago.

It's understood he has a black bull mastiff with him.

They're asking people in the area to look out for sightings of him, and report anything unusual.

He should not be approached.