CLAIMS that Iranian President Mahmoud Ahmadinejad has Jewish roots are making the rounds in the Middle East, stemming from a blog published by the son of a prominent pro-Ahmadinejad cleric.

Mehdi Khazali, whose reformist politics differ sharply from those of his clerical father, Abu al-Kassam Khazali, wrote on his website that Mr Ahmadinejad had changed his family name on his ID card from Saburjian, which, Dr Khazali said, suggested a Jewish background.

The younger Dr Khazali, director of the Hayyan Cultural Institute in Tehran, was reportedly among those arrested during the protests that followed the June 12 Iranian elections. Reports said he was summoned to a special court dealing with religious figures and transferred to an unknown location. Dr Khazali’s father is a former member of the powerful Guardian Council.

Four years ago, Britain’s The Guardian newspaper interviewed relatives of Mr Ahmadinejad and was told the family had changed its name “for a mixture of religious and economic reasons” but a Jewish angle was not mentioned.

Dr Khazali’s allegation was first made on his blog in January but it surfaced into prominence only during the election campaign. One of the candidates running against Mr Ahmadinejad, reformist Mehdi Karroubi, said during their television debate: “My full name is Mehdi Karroubi. What’s yours?”

According to an al-Arabiya television report, Mr Ahmadinejad gave his name but left out a surname that could indicate Jewish ancestry. The report did not say what that surname was.

The allegation spread beyond Iran. Bahrain’s oldest newspaper, Akhbar al-Khaleej, was shut down for two weeks when it printed the claim.

Those inclined to believe the story say it would explain the vehemence with which Mr Ahmadinejad denies the Holocaust and why he repeatedly calls for Israel’s disappearance — a desire to distance himself from any suggestion of a Jewish origin.

Scholars suggest that many Muslim families in the region have some Jewish blood, whether they are aware of it or not. Jews were part of the population of the region for about 2500 years until the foundation of Israel in 1948 forced most to flee and some intermingling was inevitable.

In the sixth century BC, Judea fell to the Babylonians and most of the residents of Jerusalem and other parts of Judea were exiled to the area of modern Iraq. Many of these exiles or their descendants returned soon afterwards to Judea but many stayed on to form thriving Jewish communities “by the waters of Babylon” that would continue to exist down to modern times.

However, a century before the Babylonian exile, there was an even more massive exile to Mesopotamia in which the Jews would lose their identity. The Assyrians had swooped on the northern Jewish tribes, the 10 tribes of Israel, and carried all of them off. Unlike the Babylonians, who permitted the Jews and all other conquered peoples to remain as distinctive ethnic groupings in exile, the Assyrians sought successfully to disconnect all the exiled nations it brought into their territory from their native ethnicity and to make Assyrians of them.

Thus the Israelite tribes disappeared from history and came to be known as the “10 lost tribes”, their members integrated into the population of the region, which includes modern-day Iran.

There are suggestions that vague folk memories remain among descendants of those ancient exiles. In some villages in Iran, Muslim residents are reported to light candles on Friday night, a Jewish practice, without knowing why.