Using testimony from five detainees, this animated film reveals the daily brutality of life inside Guantánamo. guardian.co.uk

My five-year-old is currently obsessed with writing poetry. He told me at bathtime today that he hoped to be a famous poet. I suppose this must mean that he is a nascent terrorist.

It is rare that we get an insight into the theory behind the banning of books in Guantánamo Bay, but the censors have a particular thing about poetry: "Poetry … presents a special risk, and DOD [Department of Defense] standards are to not approve the release of any poetry in its original form or language. This is based on an analysis of risk of both content and format."

My lad is named in part for my favourite poet, Wilfred Owen, whose poem Futility has twice been excluded from Guantánamo. Poetry is, you see, very dangerous: you never know what those poets mean when they write all those words. This is particularly true where a poet suggests that the "great" war may have been pointless, just because 16 million people died, many squabbling with machine guns over a very small patch of land in eastern France.

My study has turned up one other specific policy: it was the censor's view that Guantánamo detainees should be denied any materials that would help them learn English. This was a shame, as the guards thought it would be a great thing if they were able to communicate more readily with the prisoners. Be that as it may, it seemed a step too far when the censor banned The New Dinkum Aussie Dictionary.

But for the most part the censors simply do not explain their actions. We hit an opaque barrier when GT Hunt, one the Guantánamo lawyers, tried to honour detainee Saifullah Paracha's request for a Bible. Hunt sent one to a Gitmo chaplain for delivery. The next time he visited the base, Hunt received a military dressing down: delivery of the Bible would be a potentially fatal breach of prison discipline. Hunt was not qualified to take the other side – rather, we needed an evangelical minister to remind the military that, in the context of their global crusade, the Bible was the "Christian book". Indeed, I often used to drive along Interstate 10 near New Orleans, where huge billboards advertised the well-funded ministry of the Reverend Ceflo Dollar, whose name seemed so appropriate. Where was the Almighty Dollar when we needed him?

In a way, one has to respect the discriminating censor's eye, for the same fate befell a four-volume Tafsir. To no avail, the president of the American Muslim Society explained that this was a commentary on the Qur'an.

'These items were not cleared for delivery to the detainee(s)' … the cover of Jack and the Beanstalk with a note from the Guantánamo Bay censor. Photograph: Clive Stafford Smith

If there was a degree of consistency in the refusal to respect the detainees' free exercise of their religious faith, the next series of banned books was harder to understand. A colleague took in four children's titles: Puss in Boots, Cinderella, Beauty and the Beast, and Jack and the Beanstalk. All four were returned to him with the censor's annotation: "These items were not cleared for delivery to the detainee(s)." We agonised: what could be the theory behind this? Perhaps after reading Jack and the Beanstalk, the military feared that prisoners would escape by planting magic seeds?

I tried to take the magazine Runner's World into Bisher al-Rawi, who was a keen athlete. It was banned, but I got Swimming Times to him. This perplexed me, given the careful consideration that had apparently gone into the beanstalk as a means of escape. A fleet detainee who surmounted the barbed wire and sprinted past thousands of heavily armed American soldiers would still encounter the second largest land-mine field in the world before he reached "Free Cuba"; on the other hand, the swimmer could leap into the Caribbean just yards from his prison camp.

There came a point where I ceased any attempt at rational analysis, and leaned back, simply to enjoy the censor's random sense of national security. We got 1984 and Animal Farm by George Orwell into Shaker Aamer, along with Kafka's Trial – all these were surely the true bibles of the Guantánamo authorities. The Gulag Archipelago failed the test, perhaps because the military had been offended when we referred to the prison itself as a gulag. I felt that the Soviets were the ones who ought to have been offended: as of today's count, there are 162 prisoners left in Guantánamo Bay, 82 of whom have long been cleared for release – but they are still there. No Soviet gulag ever achieved a point where marginally more than 50 % of its inmates had been told they were free to go but could not leave; that seemed much more in line with 1984.

John Grisham was taken aback, but rather flattered, that The Innocent Man was rejected; since Scott Turow's Presumed Innocent had also been refused entry on to the base, one must presume that the censors have a problem with any suggestion of innocence.

A string of authors then began to compete to be barred: John Kampfner, John Pilger, Clare Short, George Galloway, and even me (should I be flattered as an "author"?). I think we were all rather proud of being on the black list. I for one had written a book about Guantánamo Bay called Bad Men, and it would clearly be a threat to national security if all the information I had got out of the prison should be allowed back in. Meanwhile I suspect the combative Jeremy Paxman was a tiny bit embarrassed that his book, The English, was allowed in.

And so la lutta libra continua. It is probably wrong for me to promise fame and fortune to writers – but if you send me your book, there is a reasonable chance that the strange censor in Guantánamo Bay will see you as an international terrorist threat. Then, like my small child with his poetry, you will be on the road to fame and fortune.

• Clive Stafford Smith is the director of the legal charity Reprieve. If you would like to test the literary taste of the Guantánamo Bay censors, please contact him at clive@reprieve.org.uk