"The guards took my Bible and stomped on it. They asked me if I was Christian or Muslim. I pointed to my cross. They said it was a big sin and beat me with their hands and sticks. From then on, I hid my cross."
Tigiste, a woman migrant who survived a Libyan detention centre, says her uncle, who is still in detention, was tortured with electric shocks and beaten by the guards. When they thought he was dead, they threw his body in the garbage.
"He was there for two days. Then someone went and touched him and he stirred."
Her story is published in a report by the Jesuit Refugee Service, which argues that the migrants' tales are credible because they are so consistent.
The JRS hopes that immigrants trying to reach Europe will stop being returned to Libya, a policy started by Italy in May, which has so far seen more than 1,400 migrants being sent back.
The detention centres are described as hopeless, dark, overcrowded and lacking basic sanitation and hygiene facilities.
Death, violence and racism are said to be the order of the day, with migrants being refused medical care and fed just two bread rolls a day.
One migrant recalls the words guards used to deny help to one of his dehydrated friends: "Here the hospital is not for black people but only for Libyans. If you want, go back and die in your country."
He says a boy, who suffered from asthma, died shortly after being told: "If you come here on your own, you die on your own."
"Many of us had scabies. Some of my friends had swollen genitals. When the guards saw this they beat them hard with a stick, put them in solitary confinement and just left them there," another migrant says.
In August, at least six people were killed and dozens injured when Libyan police quelled an outbreak of 300 detainees in one of the detention centres, according to the Fortress Europe website, quoted in the report.
"The guards smoke hashish and get high and then they hit anyone. When they do the head count, they count each person by slapping or boxing him," one of the detention survivors says.
"We went on hunger strike to leave the prison and they used electric prods to make us stop, jabbing us again and again on our muscles. I can never forget that," another migrant, Asad, is quoted as saying.
The worst thing about detention seems to be that there is no end to it, unless one pays for a way out. One migrant was only allowed to leave after paying $500; another $1,200.
However, even after this sum is paid, the migrants have to survive the dangers of the city and if caught by the police they may easily be detained again.
"Sometimes, those who paid for their freedom were re-arrested a few minutes after leaving prison," Ahmad says.
Living in Tripoli is described as a frightening prospect, living in fear of being robbed or beaten by the locals, even children.
"A little boy will come up to you and search for your money. If you refuse he will hit you, spit at you and report you to the police. You just put up your hands and allow him to check your pockets. You are nothing, he is Libyan."
Even little babies would stretch out their hands, palms upturned, because this is what they learned from their parents.
The authors of the report say a common question migrants ask is whether the international community knows what is happening in Libya, where "people treat you like livestock and exchange you for money".
One migrant said: "I soon realised that there was no big difference between the horrors I saw in Somalia and what I witnessed in the Sahara and beyond. There people dead, here people dead."
The Libyan government has not yet reacted to the damning claims made in the report, which can be accessed on www.jrsmalta.org.