TEHRAN, Iran (CNN) -- Iranian President Mahmoud Ahmadinejad on Monday called the death of Neda Agha-Soltan "suspicious" and urged the country's authorities to identify those responsible for it, Iran's semi-official Fars news agency reported Monday.

Neda Agha-Soltan has come to symbolize Iranian resistance to official election results. more photos »

The 26-year-old's death has come to symbolize Iranian resistance to the government's official election results since it was captured on amateur video. Within hours of its being posted online June 20, she had become the iconic victim of the Iranian government crackdown.

But Iran has been pushing back against eyewitness reports that she was shot by pro-government Basij militiamen perched on a rooftop near a demonstration.

Ahmadinejad told the head of Iran's judiciary, Ayatollah Hashemi Shahroudi, to probe the incident and make the results of his investigations public, Fars reported Monday, nine days after Agha-Soltan was killed. See gallery of Neda and the effect of her life »

"The massive propaganda of the foreign media, as well as other evidence, proves the interference of the enemies of the Iranian nation who want to take political advantage and darken the pure face of the Islamic republic," he said in a letter to Shahroudi, according to the news agency.

The letter comes a day after Iran's government-backed Press TV said Agha-Soltan did not die the way the opposition claims.

Two people told Press TV there were no security forces in the area when she was killed. iReport.com: Iranians share view from the streets

And the network said the type of bullet that killed her is not used by Iranian security forces.

A man who told the network that he had helped take her to a hospital said, "There were no security forces or any member of the Basij" paramilitary present when she was killed.

Press TV did not name the man, who spoke Farsi and was subtitled in English on the broadcast.

CNN has not identified him and cannot confirm his account.

"I didn't see who shot who," he said. "The whole scene looked suspicious to me."

A second man, whom Press TV identified as Agha-Soltan's music teacher, told the station there were "no security forces in this street" when he was with her during the shooting.

Press TV did not name the man, who had a gray mustache and ponytail. He also spoke Farsi and was subtitled in English as he walked and pointed at what Press TV said was the scene of the shooting in central Tehran.

Agha-Soltan was with a family friend who is a music teacher when she was killed. He appears to be the man who spoke to Press TV.

"There was no sign of a protest," he said. "We crossed the street to the other side to get a cab. ... When we reached this spot, a gunshot was heard. There was no shooting here. ... There were no security forces in this street. There were around 20, 30 people in this street. One shot was heard, and that bullet hit Neda."

"The bullet was apparently fired from a small-caliber pistol that's not used by Iranian security forces," the Press TV anchor said.

Iran has strict gun-control laws that bar private citizens from carrying firearms.

U.S. President Barack Obama said Tuesday that he had seen the video of Agha-Soltan's death and called it "heartbreaking."

"And I think anyone who sees it knows there's something fundamentally unjust about it," he said.

The shaky video of her death -- probably made on a cell phone -- shows her walking with a man near an anti-government demonstration.

After being stuck in traffic for more than an hour inside a subcompact car with a poorly working air conditioner, Agha-Soltan and the friend decided to get out of the car for some fresh air, a friend of Agha-Soltan's told CNN after her death.

The two were near where protesters were chanting in opposition to Iran's supreme leader, Ayatollah Ali Khamenei.

Agha-Soltan, wearing a baseball cap over a black scarf, a black shirt, blue jeans and tennis shoes, did not appear to be chanting and seemed to be observing the demonstration.

Suddenly, Agha-Soltan was on the ground -- felled by a gunshot wound to the chest. Several men knelt by her side and put pressure on her chest in an attempt to stop the bleeding.

"She has been shot! Someone, come and take her!" shouted one man.

By then, Agha-Soltan's eyes had rolled to her right; her body was limp.

Blood streamed from her mouth, then from her nose. For a second, her face was hidden from view as the camera went behind one of the men. When Agha-Soltan's face came back into view, it was covered with blood.

Iran's ambassador to Mexico -- one of few Iranian officials who has spoken to CNN since the disputed June 12 presidential election -- suggested that U.S. intelligence services could be responsible for her death.

"This death of Neda is very suspicious," Ambassador Mohammad Hassan Ghadiri said. "My question is, how is it that this Miss Neda is shot from behind, got shot in front of several cameras, and is shot in an area where no significant demonstration was behind held?

"Well, if the CIA wants to kill some people and attribute that to the government elements, then choosing women is an appropriate choice, because the death of a woman draws more sympathy," Ghadiri said.

CIA spokesman George Little responded, "Any suggestion that the CIA was responsible for the death of this young woman is wrong, absurd and offensive."

All About Iran • Tehran • Ayatollah Ali Khamenei