Iran's spy chief Thursday mocked US claims of a Tehran-sponsored assassination plot, saying the accusation reeked of "stupidity" and detailed incredibly unprofessional tradecraft, the website of state-run television reported.
Intelligence Minister Heydar Moslehi, who heads up Iran's espionage organisations, said the US allegations -- involving an Iranian-American used car salesman trying to contract Mexican gangsters to kill the Saudi ambassador to Washington -- were "too cheap to believe."
His point-by-point rebuttal of the US claims added to strenuous denials from other Iranian officials that Tehran had anything to do with the alleged plot.
"When you look at it from an intelligence standpoint, there are too many contradictions to believe that a government such as the United States could compile such a cheap claim and expect to it to be credible," he said.
"The initial reaction to this claim by our intelligence officers was genuine surprise at the abundance of stupidity evident in this scenario," he said.
Moslehi ridiculed US allegations that the Iranian-American, Mansour Arbabsiar, held unsecure discussions on the telephone with Iranian officials about the plot.
"I ask, what intelligence outfit, what intelligence officer, would give orders to his agent residing in enemy territory by telephone? Who gives a kill order and the location of the killing on the phone -- and even stresses that the more people killed the better?"
Moslehi, referring to details released in a US Justice Department complaint, also questioned how likely it would be that a professional Iranian intelligence officer "haggles over payment over the phone, and refers approval of extra pay to higher ranking people!"
He added: "Also, technically speaking, why would a Mexican drug cartel be used for such an operation? Why would they risk confrontation with the US over a job worth $1.5 million, while, according to the Westerners, the cartel has billions of dollars in revenue?"
The minister also asked: "Why would this 'trained terrorist' and the professional cartel exchange money via a bank in New York?"
Moslehi said "this low-quality comedy" scenario was all the evidence the United States was presenting to the UN Security Council.
The mocking tone and protestations that the alleged plot was too far-fetched to be believed have been employed by other Iranian officials.
President Mahmoud Ahmadinejad on Monday said the US allegations were "risible" and asked: "Why should we go to the United States to assassinate an ambassador of a friendly country?"
According to the US Justice Department and the FBI, Arbabsiar confessed after his arrest to trying to contract a Mexican drug cartel to assassinate the Saudi ambassador, Adel al-Jubeir, possibly through the bombing of a Washington restaurant.
He allegedly said he organised the hit on behalf of his cousin, whom he described as a high-ranking officer in the Quds Force, a shadowy special operations unit of Iran's elite Revolutionary Guards.
US officials said they became aware of the plot because Arbabsiar's contact in the cartel was in fact a paid FBI informant.
The complaint against Arbabsiar alleges that Quds Force officials transferred nearly $100,000 to the informant via a New York bank as downpayment for the $1.5-million-dollar hit.
The man US officials say was Arbabsiar's face-to-face contact in the Quds Force, Gholam Shakuri, alleged to be an aide to Arbabsiar's cousin, was also charged with trying to murder a foreign dignitary with a "weapon of mass destruction."
Shakuri is believed to be in Iran, and the United States has demanded he be extradited to face US charges, or be put on trial in Iran.