Juan Eibenschutz says a robot completed scooping up the dangerous material yesterday evening. He says the cobalt-60 was put in a safe container and is now being transported to a nuclear waste treatment facility.
The cobalt-60 was being carried in a truck that was stolen in central Mexico on December 2.
Authorities found the truck two days later with the shipping container empty. The radioactive material was then tracked down to the field near the truck.