Flame was the brainchild of the United States and Israel, a report published by American publication The Washington Post said on Tuesday, claiming that intelligence and military officials from the two nations collaborated to create and dispatch the malware, with aims to undermine Iran's controversial nuclear program.

The newspaper linked its report to earlier assertions by cyber security experts that U.S. and Israeli agents were also responsible for a separate virus, the Stuxnet, which was detected last year and purportedly unleashed to setback whatever gains have been achieved by Iran's uranium enrichment efforts.

The United States has been highly critical of the Islamic Republic's nuclear program, insisting that the country's claims of industrial goals for the clandestine project were cloaks for its intent to develop a nuclear arsenal capable of striking nearby nations in the Middle East region.

On its part, Israel believes that Tehran has been determined to launch an attack on the Jewish nation, making it a logical target of Iran in the event the latter finds success in actually coming with nuclear missiles that can hit Israeli targets.

Posturing seen from the two powerful nations makes them the usual suspects in the deployment of the twin malwares, which a blog post from Kaspersky Lab last week, said were actually engineered employing identical platforms.

The U.S.-based publication said on its report, citing unidentified sources, that Flame was created with contributions coming from personnel working for American government agencies such as the Central Intelligence Agency (CIA) and the National Security Agency (NSA).

The Israeli government also allowed its military officials to work with U.S. agents in the successful deployment of the virus, The Post said on Tuesday, which records correspondence and collects files on infected computer systems and transmits them back to the server that originally dispatched the malware.

A separate report by Reuters on Wednesday said that a number of sources, both former and current security staff working for the U.S. government, confirmed that Flame can indeed be the handiwork of agents that answer to Washington.

However, the news agency also clarified that the government offices cited by The Post on its report have yet to issue official statements on the matter as of press time.

Flame was detected last month by Iranian and United Nations cyber security experts, which called the attention of Russian-based Kaspersky Lab for deeper look into the malicious worm that is said to have infected thousands of computer systems in the Middle East, Europe and North America.

Last week, Symantec, maker of Norton Internet security tools, has reported in a blog post that Flame handlers have unleashed a 'kill command' that would annihilate the malware on infected PCs and subsequently erase any traces that would make it difficult for cyber security experts to recovers codes of the spyware.

According to Agence France Presse (AFP), experts from Kaspersky Lab and Symantec have agreed that Flame was the most challenging virus that the tech world has ever encountered, able to elude anti-virus detection on initial attack and then morph almost endlessly to dodge further discovery until its task is completed.

Its sophistication, the two security experts said, only pointed to a highly-capable and well-funded source, which they said was likely a sovereign nation or nations.