That's the report from a fringe site that's right as often as it's wrong. Word is that it occurred a few weeks ago:
On July 12, the second intercepted North Korean freighter was sunk in the Arabian Sea by torpedoes fired from a US submarine 100 miles southeast of the Iranian naval base-port of Chah Bahar. Delivery of its freight of enriched weapons-grade uranium and equipment and engines for manufacturing more fissile material including plutonium in its hold could have jump-forwarded Iran's nuclear bomb and warhead project, lopping off at least a year of work. For this Iran's rulers were ready to reportedly pay out a cool $500 million.
A few hours earlier, President Bush received an intelligence briefing on the vessel, its freight and destination. Apparently the shipment was brought forward by several weeks to evade detection by UN nuclear inspectors scheduled to visit Pyongyang this week to verify the dismantling of its nuclear facilities.
One would think this would have significantly ratcheted up the tension at the US-Iran talks a few days ago. Iran's nuclear ambitions were not on the table of course, and it might have been... touchy to add this as an agenda item -- considering the attention these talks have received.
A quick Google News search on Iran and North Korea seemed not to show anything that would support or disprove the allegation. Anyone have reason to think it might be accurate?