An Iranian general who went missing on a visit to Turkey last month appears to have defected to America, taking with him a treasure trove of his country’s most closely guarded secrets.

Ali Resa Asgari, 63, a general in the elite Revolutionary Guards and former Deputy Defence Minister, vanished on February 7 after arriving in Istanbul on a flight from Syria. He had reservations at the Ceylan Intercontinental Hotel but never checked in.

Iran has notified Interpol and raised fears that General Asgari might have been kidnapped. Yesterday, however, several sources confirmed reports in America that General Asgari had fled to the West, becoming the first senior Iran official to defect since the revolution 27 years ago.

Danny Yatom, the former head of Mossad and a member of the Knesset, said that the general could provide Western intelligence with a unique insight into Iran’s foreign operations in Lebanon and beyond.

“From the very start I thought this was a defection,” Mr Yatom told The Times. “All the signals showed that it was well planned and executed. He left Iran with his family, so that no one would be able to put pressure on them. I assume the defection was to the US.”

Mr Yatom described the missing general as very important and said that he would be able to shed light on one of the murkiest chapters in recent Middle East history. From the early 1980s Iran funded, trained and armed members of the Hezbollah movement in Lebanon, which began as a small Shia Muslim militia but is today the most powerful paramilitary force in the Levant.

The Iranians are accused of using Hezbollah to launch suicide bomb attacks against American, French and Israeli targets, to kidnap Westerners and to build a state within a state in southern Lebanon. They are also suspected of carrying out operations in Europe and even Argentina.

“He is a significant figure,” said one Western source, who follows Iran closely. “It has so far been very difficult to get reliable information on how Iran ran its operations in Lebanon. This could be a big break.”

Last summer Israel fought a bloody, 33-day war with Hezbollah after the group seized two Israeli soldiers, whose fate is unknown. At the time, Sheikh Hassan Nasrallah, the Hezbollah leader, boasted: “Israel doesn’t know our capabilities on every level. The Zionist enemy has not succeeded in infiltrating our group.” General Asgari could lift that veil of secrecy.

“It means for the first time, Hezbollah’s adversaries may have accurate estimates of stockpiles, weapons types, even perhaps placement and tactics,” said Nicholas Noe, the author of a forthcoming book on Hezbollah. “This is crucial because the limits and placement of Hezbollah’s weaponry has been a major problem.”

After Lebanon, General Asgari returned to Iran as a high-ranking official dealing with the arms trade and weapons industry, including the development of the Shaab-3 ballistic missile. He stepped down as Deputy Defence Minister in 2005. Iranian officials have played down General Asgari’s importance, saying he has been “out of the loop for four or five years. But his defectioncould cause a serious blow to Iran.

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