A young Icelandic boy's journey as an informant all began with a cryptic e-mail sent to the United States Embassy in Reykjavík.

From: [REDACTED]

To: reykjavikdatt@state.gov

Subject: Regarding an Ongoing Criminal investigation in the United States.

Date: Tue, 23 Aug 2011 03:33:39 +0000 After a quick search on the internet i have yet not been able to find a reliable contact form to establish a meeting with a person regarding an on going criminal investigation. The nature of the investigation is not something that i desire to speak over an email conversation. The nature of the intel that can be brought to light in that investigation will not be spoken over email conversation. I here by request a meeting at the U.S Embassy in Iceland, or any other place. I am an Icelandic citizen. I can be contacted via this email address Or Via Phone: [REDACTED] I request also that this email will be considered confidential.

The e-mail was from Sigurdur “Siggi” Thordarson (Sigurður Ingi Þórðarsson), then an 18-year-old.

Thordarson had been involved with WikiLeaks during the previous 18 months, moving ever-closer to the inner circle of the group—Julian Assange eventually promoted him to running the group’s IRC channel, and he was put in charge of dealing with newcomers, media, and other volunteers.

On Thursday, Wired revealed the Icelandic teenager that was part of WikiLeaks also served as a paid FBI informant, publishing months of e-mails from Thordarson to his FBI handlers (ending in February 2012) and a document entitled “Receipt for Property Received” on FBI stationary (previously only published for a short time on Thordarson's Twitter account), which detailed that the government acquired eight hard drives from Thordarson. The Icelandic informant told Ars there are more e-mails that he did not share, which continue until July 11, 2012.

Over the course of about a year, Thordarson, now 20, claims he was paid around $5,000 in cash (across three separate occasions) in exchange for his cooperation with the investigation into WikiLeaks, which included being questioned and handing over around 1TB of data across eight hard drives that included chat logs, videos, documents, pictures, and other related data to WikiLeaks.

The young man’s short time as an international man of mystery has raised significant questions as to what information the FBI and the American government have as part of its ongoing investigation into WikiLeaks. Additionally it’s curious how an Icelandic teenager who says that he previously founded a local personal security company (among other businesses in Iceland) voluntarily became a WikiLeaks informant—and many have said he has not been truthful.

Wired’s Kevin Poulsen wrote: “Thordarson’s equivocation highlights a hurdle in reporting on him: He is prone to lying. [Icelandic member of parliament Birgitta] Jónsdottír calls him ‘pathological.’ He admits he has lied to me in the past.”

Others confirm that Siggi isn't trustworthy.

"He seems practically incapable of stating anything without there being something fictitious or blatantly untrue," Smári McCarthy, an Irish-Icelandic activist based in Reykjavík, told Ars.

So why step out of the shadows now, and make public his cloak-and-dagger story?

“I thought the time was correct to come forward with this information,” he told Ars, saying that as parts of the story were coming out in the Icelandic (Google Translate) and English media, he felt that his story was not being accurately told. “It was only a matter of time before people found out who I was.”

Earlier this year, Thordarson also testified before a closed session of the Icelandic Parliament that he had been questioned by the FBI, although he denies that he disclosed being a paid informant at that hearing. As The New York Times reported earlier this week:

The F.B.I.’s activities in Iceland provide perhaps the clearest view of the government’s interest in Mr. Assange. A young online activist, Sigurdur Ingi Thordarson (known as Siggi), told a closed session of Iceland’s Parliament this year that he had been cooperating with United States agents investigating WikiLeaks at the time of the F.B.I.’s visit in 2011.

Ars spent time on Thursday speaking with Thordarson via Skype—both voice and text chat—and trying to verify his claims. The FBI did not immediately respond to Ars’ request for comment, but in the past has said that it does not comment on pending investigations.

Stepping forward

But why be an informant to begin with?

Thordarson said it was a combination of disagreeing with WikiLeaks’ tactics of information acquisition, and—more realistically—a fear of the American judicial system.

In June 2011, WikiLeaks leader Julian Assange was staying at the Ellingham Hall estate after being granted bail by an English court. Thordarson says that with Assange at his side, he asked Lulzsec’s Sabu to hack Stratfor, essentially on WikiLeaks’ behalf.

“At the end of the day by asking Sabu or anyone else to hack into a company just to leak information, then they’re breaking the law,” Thordarson said. “If [Bradley] Manning or [Edward] Snowden come forward to WikiLeaks or anyone else and provide them information without hacking their system, then they’re just a media company in publishing the information.”

Thordarson said that while he was the one in communication with the Lulzsec leader, Assange was egging him on. Thordarson didn’t know that Sabu himself had already become an FBI informant just a week earlier, but the young Icelander was afraid of getting caught.

“When you’re dealing with the Icelandic government, a life sentence is 16 years, and it’s not even used in murder cases,” Thordarson said. “But the US government doesn’t hesitate to issue charges against people that are trying to hack into government facilities or something like that,” he added, noting that’s why he approached American authorities in August 2011.

Thordarson also claimed that he did not give the FBI his entire WikiLeaks data collection.

“They didn’t know about the extra 2TB, and I haven’t told them,” he told Ars. “When they asked if I had more, I said yes, then we didn’t plan a meeting again.”

Thordarson also claims he was asked to wear a wire to record Julian Assange—and declined to do so. He says he was also flown out of Iceland four times: three times to Denmark and once to Washington DC, where he was apparently served Mexican Coca-Cola at a steakhouse dinner with a handful of intelligence agents. The international travel was meant to avoid the Icelandic government's increasing frustration with the FBI's presence on its soil.

On his final in-person meeting with the FBI in Denmark in March 2012, he handed over the eight drives totaling over 1TB, and received this receipt. The Icelander told Ars that receipt is the only written document (besides the trove of e-mails) from the FBI that he has—but he added that he did not give Ars all of his FBI correspondence, and declined to share it with Ars. He did, however, share the original embassy e-mail (quoted above).

Thordarson also claims that in February 2013, he informed three WikiLeaks staffers at a meeting in Reykjavík that he was an FBI informant, and provided them with the entire 3TB trove.

"It doesn't help me at all [to tell them], it doesn't help me to talk about this in the open," he admitted to Ars. "But I thought that if someone would talk to the FBI about me, I would like to know what he gave them. So that's why I gave them a copy."

Ars attempted to contact two of the named people (Kristinn Hrafnsson and Ingi Ingason), but they did not immediately reply. Thordarson declined to name the third person in attendance.