Fletcher case from 2004 reopened in SA

South Australian police have reopened the case into the disappearance of a man presumed murdered over a decade ago.

David Fletcher, 39, was last seen on November 6, 2004 about 6pm when he left his Magill home on a black Kawasaki motorbike.

His remains were discovered by a walker at the disused Poona Copper Mine near Moonta, approximately 120km from Port Pirie, on April 12, 2009.

Police have appealed for information to help find out what happened to Mr Fletcher.