The UN atomic watchdog begins its traditional September board meeting on Monday to discuss the current stalemate in its long-running investigation into Iran's atomic drive. The meeting, which is slated to run all week but could be wrapped up as early as Wednesday, according to some diplomats, is also expected to hear an update on state of the International Atomic Energy Agency's probe into Syria. As at previous board meetings, it will be the Iran dossier that will dominate proceedings after a new report by El Baradei accused Tehran of stalling the IAEA's investigation, refusing to provide access to documentation, individuals or sites which could reveal the true nature of its activities. The watchdog has been investigating the Islamic republic's contested nuclear drive for five years, but has so far been unable to determine whether the programme is entirely peaceful as Iran claims. The IAEA said it has obtained important new indications that an unidentified foreign expert may have assisted Iran in experiments on high explosive testing "suitable for an implosion type nuclear device".