The Guantánamo Bay files spell out the Americans' suspicions about individual detainees' involvement with terrorism, their intelligence value and the threat they are considered to pose if released. Photograph: John Moore/Getty Images

Hundreds of prisoners were captured in Afghanistan and flown to Guantánamo Bay in early 2002, where they spent years in limbo unable to speak for themselves. Their situation can only be described as a surreal equivalent of the famous short story Metamorphosis by Franz Kafka, in which a travelling salesman finds himself transformed into a giant insect, unable to talk and trapped in his bedroom.

Among the 779 men that spent time in Guantánamo was a Russian with the unfortunate pseudonym of Kafkas. Born Rasul Kudayev in the north Caucasus in 1984, he adopted the name of Abdullah Kafkas and travelled to Central Asia to further a career in wrestling.

In November 2001, according to the Guantánamo files released Sunday by WikiLeaks, Kafkas travelled to Kunduz, Afghanistan, where he "worked in an Arab medical clinic for foreign fighters". Kafkas was arrested in Afghanistan and transferred to a prison in the northern city of Mazar-i-Sharif, and then selected for detention in Guantánamo on or about 12 February 2002. Once he arrived in Cuba, however, military interrogators quickly came to the conclusion that Kafkas was "not affiliated with al-Qaida or as being a Taliban leader", and that "the information obtained from and about him (was) not valuable or tactically exploitable".

Indeed, the dossier on Kafkas, which is signed by Geoffrey Miller, the commander of the prison and dated 28 March 2002, states that Joint Task Force Guantánamo had determined that Kafkas "has no further intelligence value to the United States, and will not be seen for further intelligence purposes". Yet it took almost exactly two years for Kafkas to be released to the Russian government, on 27 February 2004. Today, over nine years after Kafkas was arrested and detained, the confirmation that he was an innocent abroad is cold comfort.

The new Guantánamo files from WikiLeaks provide proof that at least 150 people imprisoned in Guantánamo were innocent Afghans or Pakistanis, including farmers, chefs and drivers. Another 380 people were assessed as lower-level foot-soldiers. (Most of these were released in the waning years of the Bush administration.)

Take the case of Mukhibullo Abdukarimovich Umarov, born in Alisurkhan, Tajikistan, and Mazharudin, a Tajik who was born in Pajpai, Pakistan. Both men were arrested while studying at a small library in Karachi, Pakistan on 19 May 2002. Both Umarov and Mazharudin have one-page files; the two files are almost identical. They state:

"It was undetermined as to why the detainee was transferred to GTMO (Guantánamo). Since his arrival at GTMO it has been determined that this detainee is not an al-Qaida or Taliban member. There, after reviewing all relevant and reasonably available information, it is GTMO's assessment that this detainee is not an enemy combatant."

Both men were released in March 2004. In 2006, a journalist named McKenzie Funk from Mother Jones magazine accidentally heard about Umarov while travelling in the Pamir mountain region of Tajikistan and went to interview him. Funk's story, "The Man Who Has Been to America: One Guantánamo detainee's story", is a remarkable tale and very different from the cold, one-page military file that was held at Guantánamo. Umarov told Mother Jones:

"It was like being in a zoo, with people coming to stare and laugh at you. Such a prison has never existed in the history of mankind. Why did they keep a man for two years with no reason? Why? They caught me and kept me as a prisoner of war. What war, may I ask? When was I involved? I was sleeping when they came and dragged me out of my bed."

It is almost 100 years since Franz Kafka published his tale of Gregor Samsa, the travelling salesman who was transformed into an insect and trapped in his bedroom. In Kafka's tale, only sympathetic family members kept Samsa from being squashed and killed. Today, WikiLeaks, anti-war activists and many journalists have played the role of the family members to try and explain the lives of the men who have – through no fault of their own – been transformed into insects with no voices of their own.

Ironically, Abdullah Kafkas is still trapped in a Kafkasque nightmare – this time in Russia, where he was re-arrested in 2005 and transferred to in FBU IZ-7/1, a remand centre in Kabardino-Balkaria republic in Russia. Amnesty International reported on 11 March 2011 that Kafkas' health recently took a turn for the worse with the development of a high fever, cough and breathing difficulties. Doctors who provided treatment to Kafkas' lawyer were "apparently subjected to several hours of questioning recently and this presumably has increased local doctors' reluctance to become involved in the case".

Several questions still hang over every Guantánamo prisoner: will the detainees ever be truly cleared of guilt? Will the abuse of their human rights ever end? Will the prison ever close?

Now, thanks to the WikiLeaks files from Guantánamo, we know that men like Kafkas and Umarov were never guilty in the first place, even by the standards of their interrogators. Sadly, though, the answer to the latter question still appears to be no. The Washington Post has a lengthy story on how the Obama administration has now quietly scuttled its plans to try the remaining prisoners in a court of law and close Guantánamo.

Indeed, in March President Obama signed an executive order mandating that dozens of detainees in Guantánamo be imprisoned indefinitely without any charges – even though the government remains unsure of who some of the men are, let alone what, if anything, they did. One affected individual is another Tajik, Omar Hamzayavich Abdulayev. His file, released by WikiLeaks, merely notes: "Detainee's identity remains uncertain."