It was a German man who approached Iran in the late 1980s to tout the idea of buying nuclear weapons technology from a Pakistani-led nuclear black market, a new book claims.
"The Nuclear Jihadist" by Douglas Frantz and Catherine Collins tells the story of how Pakistan's nuclear scientist Abdul Qadeer Khan developed an "intricate supply network aimed at skirting sanctions and peddling uranium enrichment technology."
Khan's network supplied Libya, Iran and North Korea with restricted nuclear machinery and designs. Tehran's dealings with the network at the time remain one of the main riddles the UN nuclear watchdog in Vienna is trying urgently to solve.
The book by the US journalists says it was not Khan but German businessman Gotthard Lerch who persuaded Iran in 1987 to consider enriching uranium - a process of purifying it for use in power plants or weapons.
Lerch has been accused by German prosecutors of helping Khan supply Libya with restricted nuclear technology although he was never charged in connection with Iran and a trial on other charges was suspended last year.
Frantz and Collins say a physicist from Iran's Atomic Energy Organisation visited Lerch's office in Switzerland in 1987 to buy conventional weapons for Iran's war against Iraq.
Lerch agreed to fill the order but insisted that the Iranian watch a promotional film about his nuclear inventory. Lerch had known Khan from his days working at a German vacuum firm that sold Pakistan vacuum pumps for its enrichment programme. Several weeks later the Iranians said they were interested.
Lerch's contacts with Iran came after Saddam Hussein's Iraq began attacking Iranian troops with chemical weapons, which began to turn the tide of the long war against Tehran. Lerch met the Iranians in Zurich and then arranged a follow-up meeting in Dubai where, the authors write, Iran was expected to pay $10 million as a down-payment for several Pakistani enrichment centrifuges from Khan and designs.
Among the items the Iranians received in Dubai were partial instructions for making the core of an atomic weapon. According to the book, Lerch received $3 million of the $10 million while Khan got $2 million. The rest went to other middlemen, including another German and an Islamabad dentist.
After he was extradited from Switzerland, Lerch was tried for violating export rules in Germany last year. But the trial was suspended and it is unclear if a new trial will take place. One of Lerch's lawyers, Gottfried Reims, said he was not in a position to comment on the allegations in the book. A spokesman for Germany's Federal Prosecutor's Office said he could not comment on the book's specific allegations.
Given that Lerch's contacts with the Iranians took place 20 years ago, the statute of limitations on any export violations would have expired. A German diplomat told Reuters it was unlikely Lerch would ever be charged in connection with Iran.
In September, German engineer Gerhard Wisser pleaded guilty in South Africa to export violations in selling components to Libya and Pakistan that could be used in nuclear weapons.
In 1999, German engineer Karl-Heinz Schaab was convicted of treason for selling nuclear technology to the Iraqi government. The latest US National Intelligence Estimate says Iran halted its nuclear weapons programme in 2003. Tehran says it has no interest in acquiring atomic weapons but is pursuing nuclear power to generate electricity.