What was stolen?

The missing item is an industrial radiography device -- basically, a tool that uses a radioactive isotope to beam gamma radiation. In this case, the beam of radiation was being used to test oil pipelines for structural problems such as weakening welds.

The device uses Iridium-192, which in additional to industrial uses, is sometimes used for radiotherapy.

According to the IAEA, the missing Ir-192 was in a shielding container. According to Reuters, the shielding container is about the size of a laptop.

Whose equipment was this?

The company SGS Turkey was contracted by oil services company Weatherford to perform the tests of the pipes at an oil field in Basra using the tool. The company said the device it used is equipped with a "low-level radioactive source."

According to SGS, the equipment is kept in a secured bunker that is provided by Weatherford. The radioactive material was in the bunker when it went missing, and it is Weatherford's responsibility to secure it, SGS said in a statement. SGS said it assumes no responsibility.

Weatherford, for its part, argues the opposite. The company said in a statement that "Weatherford holds no responsibility or liability in relation to this matter."

How dangerous is the stolen material?

It's all relative, said Kevin Kamps, a radioactive waste specialist at Beyond Nuclear, an anti-nuclear advocacy group.

The half-life of Ir-192 is about 74 days -- so in the nearly four months since it went missing, it has decayed by half.

But the risk for health hazard stretches much longer -- at least 10 half-lives or as many as 20 half-lives.

The gamma rays emitted by the Ir-192 can deliver fatal doses of radiation at close range, Kamps said.

The fear of terrorists possessing the material is that it could be used to contaminate a water supply or detonate in a "dirty bomb" in an urban area, he said.

"It is shocking just how little radioactive material can do so much damage," Kamps said.

Ir-192 also releases beta rays, which can damage human skin or internal organs if ingested, he said.

If the protective shield is removed, it could be very dangerous, he said.

However, Andrew Bieniawski with the Nuclear Threat Initiative said that "while we are generally concerned about terrorists trying to acquire radioactive material, Ir-192 is not the isotope of greatest concern."

This material is in a metallic form, not a powder, which would disperse more widely if detonated by an explosive, according to Bieniawski.

What is being done?

Murtadha Kareem Khazael, a member of the Basra Provincial Council, told CNN local officials are investigating as well. Basra's governor formed a committee to look at the case to look at this "serious claim," he said.

The committee's report is due this weekend, said Khazael, adding that "based on it, we will take important decisions."

The IAEA said it offered Iraqi officials assistance, but that Iraq has not taken it up on its offer.

"No assistance has been requested so far through the Incident and Emergency Centre (IEC), the IAEA's contact point," the international body said in a statement.

While the provincial government confirmed the theft, a spokesman for the country's Ministry of Environment said his office lacked information on the incident. Spokesman Ameer Al -Hassun said the ministry cannot deny or confirm the theft until more information is available.