Tiny but deadly radioactive capsule missing in Western Australia has been miraculously found.

A small but deadly radioactive capsule has been found missing from Western Australia after it fell off a truck.

WA authorities confirmed on Wednesday that the radioactive substance lost for three weeks was located at 11am and contained after an extensive search along a remote stretch of road.

The successful search for the 8mm by 6mm caesium-137 capsule, along a 1,400km route, has been likened to finding “a needle in a haystack”.

The exact spot, just south of Newman, WA, where desperate search teams found the small caesium-137-containing object six feet from the roadside on Great Northern Highway.

The object was detected by a search vehicle traveling at 70 km/h when a specialized team detected the radiation emitted by the capsule.

The pod was located just south of Newman on the Great Northern Highway.

A search vehicle was traveling at 70 km/h when a specialized team detected the radiation and then a portable equipment was used to locate it two meters from the edge of the road.

The search teams included specialists from the Australian Organization for Nuclear Science and Technology and the Department of Fire and Emergency Services (DFES).

Crews had spent six days scouring the highway in search of the capsule, which can cause radiation burns or illness or even death if handled.

Emergency Services Minister Stephen Dawson said the discovery was remarkable considering the scope of the search.

“This is an extraordinary result…they have literally found the needle in the haystack,” he said.

WA government officials said the capsule had been found on Wednesday just south of Newman on the Great Northern Highway.

A government investigation into the incident has been launched and a report will be provided to the health minister.

While the capsule was lost, urgent warnings were issued that anyone who believed they might have touched it should “seek immediate medical attention…or visit a hospital emergency department.”

But the panic over the cancer-causing object is officially over with Western Australian authorities heaving a huge sigh of relief.

“The radioactive substance has been found and no longer poses a risk to the community,” the Department of Fire and Emergency Services (DFES) said in a statement.

The 8mm by 6mm object fell from a density gauge while being trucked from a Rio Tinto mine in the Pilbara to Perth last month.

A Rio Tinto spokesman confirmed that an expert in handling radioactive materials lost the missing capsule.

Emergency services found a small radioactive capsule near Newman, ending a full-scale, inter-agency search for the missing item.

Defense officials are checking the identification of the capsule that was placed in a lead container for safety.

It will be stored in a secure location in Newman before being transported to a Perth health facility.

Health director Andy Robertson said the pod did not appear to have moved and no injuries had been reported.

“The substance has been safely recovered and will be transported securely in a lead container to Newman for overnight storage before it is transported to a WA health facility in Perth tomorrow, Thursday 2 February.”

Dr Robertson said that despite its size, the capsule contained “a fairly large dose of radiation”.

He compared it to “getting about 10 X-rays an hour…the amount of natural radiation we’d get in a year just by walking around.”

A small but deadly radioactive capsule missing in Western Australia was miraculously found on an outback road (workers during search pictured)