Authorities in Washington investigated a report of human remains in a cave on a river and instead found the sunken skull was actually a plastic beer bong.

An officer responded when a paddle boarder reported seeing human remains in a cave on the Pend Oreille River, near the Canadian border.

The investigators took jet skis to the cave entrance and swam inside, where they spotted what appeared to be a skull underwater inside the cave.

The apparent skeletal remains turned out to be a plastic beer bong shaped like a skull and spinal column.

The beer bong had been filled with rocks, leading investigators to suspect it was intentionally placed under the water as a prank.