Communications flaw led to 'dozens of CIA spy deaths'

"We're still dealing with the fallout," said one former official. "Dozens of people around the world were killed because of this."

According to the sources, the online platform was initilly employed in the Middle East to allow communication with soldiers in war zones. It was later adopted by intelligence agents, despite its flaws.

It is reported that Iran began uncovering the flaw when it began rooting out spies in response to the Obama administrations discovery of a secret weapons factory.

US officials say that Iranian agents were able to use popular search engine Google to find secret CIA websites. This allowed Tehran to infiltrate the spy network by 2011, when in May of that year it announced that it had busted a network of 30 US agents.

The discovery led to the execution and imprisonment of several of the informants, according to the sources.

Thirty US operatives were also executed in China following Beijing's discovery of the communications flaw. It is believed that Beijing and Tehran had shared intelligence in order to crack down on US intelligence agents.

In Russia, however, a CIA agent warned about the attacks before Moscow could uncover information about spies in the country.

The US was reportedly warned about the system's flaws by defence contractor John Reidy in 2008, prior to the breach.

According to Reidy's statement, up to 70 percent of operations at the time may have already have been compromised. According to the Yahoo report, Reidy was sacked over "conflicts of interest".

The communications failure was discussed in a secret hearing by the US House and Senate Intelligence committee, however, to date there has been no accountability for the deaths of the agents exposed by the flaw.

"This is one of the most catastrophic intelligence failures since September 11th," said Irvin McCullough, a national security analyst with the Government Accountability Project. "And the CIA punished the person who brought the problem to light."