When the Iranian asylum seeker says that he cannot pinpoint the year he started handing secret service photographs and films to the Kurdish Democratic party, nobody in court 3 looks surprised.

The appellant’s solicitor stares at his hands, the immigration judge does not glance up from his notes and the eyes of the Home Office presenting officer remain still.

Flustered, Rasoul, a short, middle-aged man, senses that he has said the wrong thing and dabs at his dry eyes with a tissue. By way of excuse, he says in Farsi: “I can’t even remember what I ate yesterday for lunch.” As the only evidence to support his case is his account, a bad memory is good defence. As these are civil proceedings, he is not even under oath.

Rasoul arrived in Britain a few months ago, trafficked here from Turkey through France and possibly Greece as well, although he cannot say for sure. When he was arrested in Leicester he claimed asylum saying that he feared persecution by the Iranian authorities on his return. Like 89% of applicants his initial plea was refused by the Home Office so he has ended up in Taylor House, London, one of 15 centres in the country where Asylum and Immigration Tribunals are held; 55,975 people applied for asylum last year, 78% of appeals were denied.

Despite these odds, the waiting room is strangely jolly. Taylor House is in Clerkenwell, a fashionable enclave of central London, and it would be hard to tell most here from the media types in the neighbouring offices. A Turkish man and a Sri Lankan man swap e-mail addresses while young women with nice handbags admire one another’s babies. It is a long way from the world they describe in the 21 hearing rooms.

Rasoul is now well into his tale of international espionage. The former manager of a photo shop tells of a prison stint for developing “morally offensive” photographs of women in sleeveless tops and a period spent locked in a basement by “mafia”.

The saga is muddled and were he telling it in the pub you probably would not believe him. Nevertheless his claims — which the court may yet find to be true — are by no means outlandish. In Taylor House, where all sides concede that appellants will exaggerate, embellish and tell outright lies, his story is pretty tame.

Judges hear from political activists who claim to be Zimbabwean but can speak none of the country’s languages, from Indian men who eat beef and from the Chinese “Catholic” who asked to remain here on religious grounds. In cross-examination she could identify neither Jesus nor the Bible. When asked how long she had been a Catholic she replied, “Two weeks.”

“At the moment judges are seeing a lot of what we call ‘rooftop homosexuality’,” says Khurshid Drabu, a senior immigration judge who has worked with asylum seekers for 30 years. “Appellants say, ‘I was caught in a homosexual act on the rooftop in Iran and three or four mullahs were watching me and I haven’t got a chance if I go back’.” He sighs. “It’s obvious that these cases are facsimiled by human traffickers.”

Each appeal, no matter how suspect, is accorded the proper time and consideration. Judges see about three cases a day. “Very often I have sleepless nights,” says Drabu, “not because I have any particular sympathy for any case but simply because most of the cases lack evidence.”

Without evidence, the judges are left only with stories. In an effort to counter this some appellants produce “official documents” which appear distinctly home-made. In court 4, a young Sri Lankan man’s family submits a word processed letter amended in ballpoint pen that they claim is a warning from the police back home.

Others produce photocopies of photocopies of membership cards to illegal political organisations that they may never have heard of. It is also common for asylum seekers to claim they are from countries other than their own — current favourites are Afghanistan and Zimbabwe — as it can give them a better shot at being allowed to stay.

To qualify for asylum status an applicant’s story does not need to be plausible so long as it is not “manifestly incredible”. Even with this low standard of proof, only about one fifth of asylum seekers are successful which gives some indication of the number of glaringly fictitious accounts over which the judges deliberate.

“The system is arbitrary,” says one barrister, a Taylor House regular. “It all rests on whether a judge thinks someone is telling the truth.” It can therefore fail in a fundamental way by letting the bogus in and kicking the needy out.

Rasoul bows his head to hear judgment. His case, like all the others that day, is resolved with a whimper. The judge will write to him with his decision. If asylum is granted, will it be fair? If not, will it matter? Rasoul could well join the 75% of failed asylum seekers who are never successfully deported.