United States-On the night of August 7, residents of a middle-class neighborhood in northern Tehran heard shooting. Some of them rushed out to see what had happened.

Slumped in a white Renault was a middle-aged man and a younger woman. Both were dead. At least four shots had been fired at them; another had hit a passing car. The two assailants had been on a motorbike, according to Iranian news agencies.

One witness told a local journalist: “We were told there was a shooting. We went to the scene and saw they are shot dead. There were two of them.” Within hours semi-official Iranian news agencies were reporting the murders of a Lebanese academic called Habib Dawood with ties to the Lebanese group Hezbollah -- and his daughter, Maryam. There was no explanation of the killings, and no arrests reported.  But at least one Iranian news agency, FARS, later dropped the identities of the victims from its reporting.

And there the story rested, until a flurry of activity on obscure social media accounts in mid-October, claiming that the victims were not Lebanese, but rather one of the most important figures in al Qaeda -- Abu Mohammed al-Masri -- and his daughter, Miriam, the widow of Osama bin Laden’s son Hamza.

The original reports about the mysterious Dawood seemed suspect because there was no record of a Lebanese academic by the name of Habib Dawood, nor anyone with a similar spelling. Nor was there any eulogy in Lebanon -- for either him or his daughter. And there was nothing in pro-Hezbollah media in Lebanon to verify the identity of the victims. In mid-October, a Twitter account called “AnbaJassim” -- purportedly belonging to a freelance journalist in the United Arab Emirates posted a screed suggesting it was al-Masri and his daughter who had been killed.

Abu Mohammed al-Masri and his daughter, Miriam, the widow of Osama bin Laden’s son Hamza, were killed in Tehran this year.

AnbaJassim said he had asked jihadi veterans of the Afghan wars, and “their response confirmed to me that those killed are Abu Muhammad al-Masri” and his 27-year old daughter.

Two weeks later an agency called Shamshad News, which describes itself as an Afghanistan-based radio and television news outlet, also claimed that al-Masri had been killed in Tehran. But the Iranian authorities remained silent.

On Friday, a senior counterterrorism official told CNN “that Abu Muhammad al-Masri is probably dead.”

The New York Times first reported the killing of al-Masri and his daughter, citing unnamed officials as saying Israel carried out the attack.

The Israeli Prime Minister’s office has refused to comment on the report. Iran’s Foreign Ministry spokesman Saeed Khatibzadeh said in a statement that Washington and Tel Aviv “spread lies” to “portray Iran as associated with these terrorist groups.”

The “media must not be a tribune for spreading and broadcasting the intentional made-up lies uttered by the White House against Iran,” Khatibzadeh added.

he death of Al-Masri, whose real name was Abdullah Ahmed Abdullah, deprives al Qaeda of one of its best planners and most experienced operatives. A 57-year old Egyptian, he was widely thought to have been the brains behind the attacks on the US embassies in Nairobi and Dar es Salaam on August 7, 1998 -- 22 years to the day before the shooting in Tehran.

Al-Masri was a “charter” member of al Qaeda, according to documents recovered from Afghanistan by US investigators in 2001.