Diesel slick on Perth's Swan River

Absorption materials have been deployed on Perth's Swan River to contain a 500-metre diesel slick.

Efforts are underway to contain a 500-metre diesel slick on Perth's Swan River.

Department of Parks and Wildlife riverpark manager Roland Mau said the source of the slick was not yet known.

"We have deployed absorption booms to contain the spill and recover as much diesel as we can," Mr Mau said.