A mysterious radiation release that has indefinitely closed the US government's only permanent nuclear waste dump might have been caused by kitty litter.
Officials are following up a theory that the leak, at the Waste Isolation Pilot Plant in the Chihuahuan Desert in New Mexico, was caused by a switch in the type of kitty litter that is mixed with the toxic waste.
The Carlsbad Current-Argus website reported that a scientist who worked at the facility until 2010 believes a change from non-organic to organic litter caused a chemical reaction inside a waste drum, releasing the radioactive isotopes.
New Mexico Environment Department Secretary Ryan Flynn confirmed he has heard Department of Energy officials discuss the possibility that kitty litter might have been to blame for the leak.
Mr Flynn stressed it is just one of many theories the department is exploring.