North Korea sent Iran software that could be used to develop nuclear weapons, a German news report said Wednesday, citing unidentified Western intelligence sources.
Pyongyang also sent a team of scientists to Iran in February to train about 20 employees of its Defence Ministry in the operation of the neutron flow simulation program, the Sueddeutche Zeitung reported.
Calculating neutron flow in radioactive material allows scientists to determine when a chain reaction, or explosion, would occur. This information is essential for designing nuclear power reactors that do not explode and for building nuclear bombs that do, DPA reported.
Western countries suspect Iran is aiming to produce nuclear warheads. Tehran insists it is only enriching uranium for power generation and medical purposes.
North Korea is suspected of helping Iran with its nuclear programme in return for 100 million dollars, which experts said would far exceed the cost of the training and software provided this year, the news report said.
On Saturday, Tehran said it would unveil a new cruise missile within the week with a longer range than the current Shahab 3, which has already raised concerns with its 2,000-kilometre range, covering all of arch-foe Israel.
On Monday, Iranian news reports said authorities had started transferring the first of 3,000 centrifuges for enriching uranium to a new plant in Fordo, north of Tehran.
The facility would be the country's second enrichment plant after Natanz in central Iran.
North Korea tested nuclear bombs in 2006 and 2009. The isolated communist country is thought to have helped Syria build a nuclear facility that Israel bombed in 2007.