A missing radioactive capsule used in Rio Tinto‘s mining operations that sparked a radiation alert in Western Australia has been found.

The stainless steel 6 millimeter by 8 millimeter (0.24 inch by 0.32 inch) device is part of a gauge used for measuring the density of iron ore feed and fell off the back of a truck operated by a specialist third party.

The capsule was reported missing after a 1,400-kilometer (870 mile) journey through a rural region. The gauge was being taken to a specialist center in Perth for repairs and arrived on Jan. 16. But the capsule was not discovered missing until Jan. 25 and is thought to have come loose on the bumpy road.

Emergency services conducted a huge search operation to find the device, which they warned could cause radiation burns or radiation sickness from close exposure, despite a low risk to the public due to its size and remoteness. Anglo-Australian mining giant Rio Tinto said it was assisting in the operation.

Western Australian authorities said Wednesday the device had been controlled and contained.

It was found by the side of the road on the Great Northern Highway near the town of Newman, which is around 1,100 kilometers north of Perth.

Emergency service workers and a team from Australia’s Nuclear Science and Technology Organization located it after a slow-moving roadside hunt using specialized radiation equipment.

Authorities said it would now be transported securely to a Western Australia health facility in Perth.

The company’s iron ore chief executive, Simon Trott, on Monday apologized for causing alarm.

In a statement Wednesday, Trott thanked emergency services for their work.

“While the recovery of the capsule is a great testament to the skill and tenacity of the search team, the fact is it should never have been lost in the first place. I’d like to apologise to the wider community of Western Australia for the concern it has generated,” he said.

Trott added this kind of incident was rare but the company was undertaking an investigation into how it occurred and whether the use of specialist contractors to package and transport radioactive materials was appropriate.