Russian nuclear scientists are providing technical assistance to Iran's attempts activate the country's first nuclear power plant at the Gulf port.
But they have raised serious concerns about the extensive damage caused to the plant's computer systems by the mysterious Stuxnet virus, which was discovered last year and is widely believed to have been the result of a sophisticated joint US-Israeli cyber attack.
According to Western intelligence reports, Russian scientists warned the Kremlin that they could be facing "another Chernobyl" if they were forced to comply with Iran's tight deadline to activate the complex this summer.
After decades of delays over the plant, which was first commissioned by the Shah in the 1970s, Iran's leaders are demanding that scientists stick to the schedule set last year. They argue that any delay would be a blow to Iran's international prestige.
Russian scientists working at the plant have become so concerned by Iran's apparent disregard for nuclear safety issues that they have lobbied the Kremlin directly to postpone activation until at least the end of the year, so that a proper assessment can be made of the damage caused to its computer operations by Stuxnet.
The Iranian government is bitterly opposed to any further delay, which it would regard as another blow to national pride on a project that is more than a decade behind schedule. While Western intelligence officials believe Iran's nuclear programme is aimed at producing nuclear weapons, Iran insists the project's goals are peaceful.
The Russian scientists' report to the Kremlin, a copy of which has been seen by The Daily Telegraph, concludes that, despite "performing simple, basic tests" on the Bushehr reactor, the Russian team "cannot guarantee safe activation of the reactor".
It also accuses the Iranian management team, which is under intense political pressure to stick to the deadline, of "not exhibiting the professional and moral responsibility" that is normally required. They accuse the Iranians of having "disregard for human life" and warn that Russia could find itself blamed for "another Chernobyl" if it allows Bushehr to go ahead.Shame on me for not being able to stop grinning at the idea of an Iranian Chernobyl.