Authorities are stepping up their search for a tiny, highly radioactive capsule, which they believe fell from a truck while being transported through Western Australia.
The silver capsule contains a small amount of caesium-137, and is dangerously radioactive. An hour of exposure from about a metre away is the equivalent of having 10 X-rays, and prolonged contact can cause skin burns, acute radiation sickness and cancer, experts said.
The lost device is part of a density gauge, which is used to measure density of iron ore feed.
The gauge was being transported by a subcontracted company, who picked it up from the mine site on 12 January to move it to a storage facility in the north-east suburbs of Perth.
When it was unpacked for inspection on 25 January the gauge was found broken apart and the radioactive capsule was gone. The authorities said vibrations during transit may have caused bolts from the gauge to become loose, allowing the capsule to fall through gaps in the casing and truck.
There are also concerns the solid capsule may have already become lodged in another vehicle's tyre and potentially be hundreds of kilometres away from the search area.