Iran is using the Gulf port of Dubai to smuggle sophisticated electronic and computer equipment for its controversial uranium enrichment programme that are banned under United Nations sanctions.
In the latest deal, an Iranian company associated with the regime's nuclear programme has acquired control systems from one of Germany's leading electronics manufacturers. The deal was negotiated with a prominent Dubai trading company, which then sold Iran a range of electronic equipment for use at its Natanz uranium enrichment facility.
Details of the deal have emerged amid mounting concern in the West that Tehran has ended its self-imposed suspension of its nuclear weapons programme. A National Intelligence Estimate issued by US intelligence agencies in late 2007 concluded that Iran had suspended its attempts to build an atom bomb in 2003.
But a detailed assessment of Iran's recent declarations to the International Atomic Energy Agency (IAEA) in Vienna has led Western officials to conclude that Iran has ended its self-imposed suspension, and has now resumed work on its military programme.
This would explain Iran's renewed attempts to smuggle banned equipment through Dubai. In the latest deal, details of which have been obtained exclusively by The Sunday Telegraph, high-grade German equipment including computers, controllers, communication cards and cables have been smuggled into Iran.
The equipment was sold to Iran without the knowledge of its German manufacturer by a Dubai-based intermediary using false end-user certificates for companies in Asia, even though the sale of technology that can be used in Iran's nuclear programme is banned under UN Security Council resolutions.
The equipment was delivered to Kalaye Electric, an Iranian company which is also subject to sanctions because of its close association with Iran's nuclear programme. Kalaye Electric is responsible for the procurement and development of the centrifuges that are used at Natanz to enrich uranium.
The smuggling accusations were denied by Iran, which insists its nuclear programme is entirely peaceful. Its ambassador to London, Rasoul Movahedian, added that the country had no need to import or smuggle technical components.
American and UN officials last month launched an investigation into how Iran had managed to acquire nuclear valves and other restricted components from Western companies in breach of UN resolutions. They have now extended their inquiry to Dubai, which is already under intense pressure from Washington to prevent the transfer of technology to Iran.
Last year the Dubai authorities blocked the sale to Iran by the Dubai-based company Scientechnic of equipment manufactured by the German electronics company Siemens, which has since given an undertaking not to supply any of the corporation's equipment to Iran.
"The Iranians are still managing to smuggle sophisticated technology through Dubai for its nuclear programme by using false certificates and unscrupulous intermediaries," said a senior UN source. "We need the Dubai authorities to be more rigorous in preventing the transfer of this equipment to Iran."
The equipment is vital for the Natanz enrichment facility, which last year experienced technical difficulties with the centrifuges used to enrich uranium.
The allegations that Iran is continuing its efforts to acquire banned electronic technology for its nuclear programme comes as Tehran attempts to avoid a new round of UN sanctions.
Iranian officials have presented the IAEA with details of a proposal to ship stockpiles of enriched uranium to Turkey as part of a deal negotiated with Brazil to resolve the international crisis over Iran's nuclear programme.
Under the terms of the proposed deal Tehran would ship about half of its 2.5 tonne stockpile of enriched uranium to Turkey. In return the West would provide Iran with processed nuclear material for its medical research reactor in Tehran.
Iran originally agreed to ship its stockpiles of enriched uranium to Russia under the terms of an agreement negotiated in Geneva last October, as part of a confidence-building measure to defuse the crisis. But the deal was blocked by Iranian President Mahmoud Ahmadinejad. Now Tehran is proposing to send a smaller quantity of its enriched uranium to Turkey, which has only limited nuclear processing facilities.
Western officials believe Iran has only made the offer in a last-ditch attempt to avoid the implementation of a new round of UN sanctions after US President Barack Obama secured the backing of China and Russia for a new security council resolution.
Futhermore there is mounting concern among Western counter-proliferation experts that Iran has resumed its nuclear weapons programme, which was halted in 2003 following the US-led invasion of neighbouring Iraq.
Western officials have been conducting a rigorous re-assessment of Iran's nuclear programme since the CIA published its controversial National Intelligence Estimate in 2007 which questioned whether Iran still had an active weapons programme.
Following an exhaustive investigation of the reports on Iran compiled by UN nuclear inspectors working for the IAEA, Western officials are convinced that Iran has secretly resumed work on building an atom bomb.
"When you look in detail at Iran's declarations on its nuclear programme, the only logical conclusion that can be drawn is that Iran has only one aim, and that is to build nuclear weapons," said a senior Western counter-proliferation official.