Step into the former shelter, which was reopened on September 11, 2008, and you are greeted by harsh white light reflecting off high granite walls. The entrance to the highly secure underground servers being used by WikiLeaks in Sweden. As you walk towards the office area buried 30 metres underground, two old German submarine engines lie along the narrow tunnel-like corridors - repurposed as emergency back-up generators. Beside them, the submarine's emergency horns emit a loud buzzing noise when pressed. There are three levels of back-up for the servers, which are housed in a 1200 square-metre area decorated with wall plants, artificial waterfalls and a 2600-litre saltwater fish tank. Above the main room a long, suspended glass corridor leads to a round see-through meeting room bolted directly below the ceiling, with a moon-map fur rug covering its floor.

"The business we do needs ultra security," Bahnhof's chief executive Jon Karlung told Data Centre Pulse in 2009. "We need high-tech facilities to protect our equipment and also make our clients safe and secure in this environment, so it is ideal for serving and hosting business." This is not the first time that WikiLeaks has turned to Bahnhof. It had previously used Bahnhof's servers to house its data - including some of its Iraq War Logs documents - around August, Mr Karlung said. WikiLeaks also spreads its private data and hosting servers across the globe to minimise its risk of being completely overwhelmed by cyber attacks.

But the thematic data centre - inspired by the 1970s cult film Silent Running and other espionage and sci-fiction movies from the same era - aptly reflects the international yet stateless and enigmatic nature of WikiLeaks. But despite the controversy surrounding WikiLeaks, Bahnhof, unlike webhost Amazon, online financial services company PayPal and DNS (Domain Name System) provider EveryDNS - all US-based organisations - says it will stand by WikiLeaks as it has not broken any laws. "We do not shut down clients unless there are solid legal claims to do so from the appropriate authorities and in Sweden that would be the Swedish authorities and not American authorities, and not an American senator," Karlung told Germany's international broadcaster Deutsche Welle, taking a dig at US Senator Joe Lieberman, who allegedly pressured Amazon and PayPal to drop WikiLeaks as its customer. "They have to come forward with a court order or something similar that makes it clear that this is something illegal, and there are no signs whatsoever that this material is illegal in Sweden," he said to Forbes magazine. “[Someone saying] 'we prefer you don't host them' is not enough.”

WikiLeaks said it has come under "heavy" cyber attack in the past week as it released gradually released its cache of more than 250,000 diplomatic cables. It switched its domain name to WikiLeaks.ch from WikiLeaks.org after everyDNS withdraw its support for the site. Today, the non-profit organisation re-released a list of 355 mirror sites, "in order to make it impossible to ever fully remove WikiLeaks from the internet". The mirror sites replicate WikiLeaks' data. The organisation has also started offering its archives for download through BitTorrent - the sharing of files through computers connected to the internet. "Due to recent attacks on our infrastructure, we've decided to make sure everyone can reach our content. As part of this process we're releasing archived copy of all files we ever released," WikiLeaks said on its site.

It has also posted a 1.4GB file encrypted with a 256-digit key that is said to be unbreakable for anyone to download in the event "something happens to us". WikiLeaks' founder Julian Assange explained in a live blog on The Guardian on Friday: "The Cable Gate archive has been spread, along with significant material from the US and other countries to over 100,000 people in encrypted form. "If something happens to us, the key parts will be released automatically. Further, the Cable Gate archives is in the hands of multiple news organisations. History will win. The world will be elevated to a better place." Attorney-General Robert McClelland said today Assange had the right to return home as a Australian citizen and that he would be accorded procedural fairness. But he added that under international agreements, Australia was obliged to assist law enforcement agencies in other jurisdictions.

In the United States, politicians continued to call for Assange's arrest, with Republican Mitch McConnell labelling the 39-year-old a "high-tech terrorist". "He has done enormous damage to our country, and I think he needs to be prosecuted to the fullest extent of the law," he told US television network CBS yesterday. Loading with AFP/AAP