Moscow’s Sheremetyevo airport, until recently the home of whistleblower Edward Snowden, has now been reported to hold another secret: €20bn in cash unclaimed for the past six years.

That’s enough money to cover the EU’s predicted budget shortfall for 2013. Nonetheless, no one is sure who it belongs to, and many doubt its very existence. Some sources have said it was sent by Saddam Hussein, while others offer the government of Iran as the owner.

According to a Russian intelligence agency source, those trying to claim it allegedly include Ukrainian spies, Chechen gangsters, al-Qa'ida members and even the Knights of Malta. The Knights, for one, flatly deny the suggestion however, and say they have nothing whatsoever to do with such claims.

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On 7 August, 2007, security company Brink’s flew from Frankfurt to Moscow and delivered 200 wooden pallets with €20bn in €100-notes owned by one “Farzin Koroorian Motlagh”, according to a Sheremetyevo delivery document printed by the newspaper Moskovsky Komsomolets, which broke the story. The document does not list a recipient. Several Russian intelligence agencies took control of the shipment, which has not yet been claimed, the newspaper reported.

A source in a Russian intelligence agency reportedly told Moskovsky Komsomolets that the money could belong to Saddam Hussein, who allegedly had $12bn in cash brought to Moscow in 2002 and invested in real estate. But the source warned against digging too deep, saying: “This is more dangerous than you can imagine.”

In a subsequent article, an intelligence agency source calling himself “Ivan” reportedly told the newspaper that the US government had long ago sent two Federal Reserve officers to Iran with a money-printing press to pay for oil it had bought. When US-Iranian relations went sour, the Iranians were left with $6 trillion in cash they couldn’t use. The $6 trillion was transported to Frankfurt, Ivan continued, where it was converted at a disadvantageous rate into €3 trillion. Brink’s then delivered this money to 27 countries, including Russia.

Motlagh was one of three people the Iranian government entrusted with picking up the money, but he tried to steal one of the shipments in Abu Dhabi and then suffered a suspicious heart attack in the custody of Iranian intelligence, Ivan said.

A Facebook page for “Farzin Kororian Motlagh” created in 2012 shows a man resembling the one shown on an Iranian passport published by Moskovsky Komsomolets.

Fraudsters including Armenians, Turks, Kurds, Japanese, members of al-Qa’ida and the Knights of Malta tried to claim the money, as did a foundation called “World of Kind People” run by Ukrainian intelligence agents, according to Ivan.

The Sovereign Military Order of Malta (Knights of Malta) contacted The Independent after this article was first published to make clear they have made no claim on the Moscow airport money. The article has been amended to reflect their position.