WASHINGTON — A prize-winning Iranian nuclear scientist has died in mysterious circumstances, according to Radio Farda, which is funded by the U.S. State Department and broadcasts to Iran.

An intelligence source suggested that Ardeshire Hassanpour, 44, a nuclear physicist, had been assassinated by Mossad, the Israeli security service.

Hassanpour worked at a plant in Isfahan where uranium hexafluoride gas is produced. The gas is needed to enrich uranium in another plant at Natanz which has become the focus of concerns that Iran may be developing nuclear weapons.

According to Radio Farda, Iranian reports of Hassanpour’s death emerged on Jan. 21 after a delay of six days, giving the cause as “gas poisoning”. The Iranian reports did not say how or where Hassanpour was poisoned but his death was said to have been announced at a conference on nuclear safety.

Is this the work of Israel, who knows but it does follow the same pattern as Egypt and the Nazi scientist in the 1950's and the Iraqi scientist in the 1980's.