A German expert on nuclear proliferation claims Iran has carried out two nuclear tests on the territory of its ally North Korea, contesting the widespread belief that the Islamic Republic is not yet able to build nuclear weapons.

“By now, several intelligence agencies assume that North Korea in 2010 indeed performed one nuclear test for Iran,” Hans Rühle, formerly a senior official in the German Defense Ministry, asserted Sunday in the daily Die Welt. Rühle said a second North Korean test was also carried out that year on Iran’s behalf.

On the same day, US President Barack Obama, speaking at the annual conference of the pro-Israel lobby AIPAC, said that the United States and Israel “both assess that Iran does not yet have a nuclear weapon.”

Rühle based his speculations on the research of a Swedish nuclear physicist, Lars-Erik de Geer, an analyst for a Stockholm-based research institute. While de Geer assumes that North Korea secretly performed two tests of its own nuclear weapons in 2010, Rühle believes that the reclusive Communist regime was actually testing Iranian weapons.

North Korea publicized past nuclear tests, he wrote, but kept those two secret, raising questions about their nature.

In 2006 and 2009, the North Korean regime boasted that it had conducted successful nuclear tests.

“What’s sensational about de Geer’s finding is that the source material for these tests was uranium,” Rühle wrote. North Korea long maintained it did not possess weapons-grade uranium, he wrote, and in the tests in 2006 and 2009 the weapons contained a different substance, plutonium.

Only two explanations could explain the uranium used in the two mysterious tests performed in 2010, he wrote: Either Pyongyang used material it had started enriching in secret, or was performing tests for a foreign nation, in this case probably Iran.

“This would be a sensation, but hardly surprising,” he wrote. “For years intelligence agencies have noticed close cooperation between North Korean and Iranian experts regarding the preparation of nuclear tests.”

The International Atomic Energy Agency, or IAEA, insists  the Iranian regime does not have the capability to develop nuclear weapons.

Rühle, who headed the planning staff of the Defense Ministry in Bonn from 1982 to 1988, says he expects that all involved parties will deny his theory. In any case, he wrote, it won’t have immediate practical consequences aside from further “poisoning the political atmosphere.”

If it turned out to be true, it would cause further turmoil in the Middle East and prove that US President Barack Obama’s policy of nonproliferation failed, he added. “The various American intelligence agencies will make sure this remains disputed,” Rühle wrote. “A few months before President Obama seeks to be reelected he cannot afford to have his foreign policy fall apart.”

Last month, Pyongyang made the surprise announcement that it was ready to halt its uranium-enrichment program and its nuclear missile tests in return for aid from the US.

In a February article also published in Die Welt , Rühle wrote that contrary to some assessments Israel’s air force could easily destroy Iran’s nuclear facilities.