Omar Deghayes, a 37-year-old Libyan refugee from Saltdean, has been imprisoned at Guantanamo Bay for almost four years. The plight of the detainees, kept in small cages without access to family or friends, allegedly suffering constant abuse, torture and humiliation, has been well documented and condemned by many.

What goes mostly unnoticed is the devastating effect on the families of the men that have been incarcerated. Their relatives are also being punished. They know their loved ones are suffering but are powerless to help, they are unable to telephone or visit and don't know if they will ever be reunited.

Here, for the first time, Mr Deghayes' mother Zohra Zewawi, 67, describes the anguish she goes through every day that her son remains a prisoner, cut off from her and the rest of the world.

Whenever I try to express my feelings of sadness due to my beloved son's absence, I find my brain incapable of doing so.

Whenever I remember him in my mind or in my soul, the tears pour out of my eyes and I cannot stop them at all.

The tears feel as if they would go on for eternity.

How can I tolerate my existence in this house without him? I find his smell in every corner of the house where he lived.

How do I cope with the knowledge that we eat everything we like while he does not eat even a little or the fact that we sleep on our comfortable beds while he does not even get to sleep?

Instead he is tortured to prevent him from sleeping.

Every morning when I get up and wash my face with clean warm water and perform the ritual ablution in order to pray, I remember him and how he does not even have water.

So how do you think I feel thinking of my son in a cold narrow cell without sunshine or fresh air?

I cannot sleep at night because of the sadness I feel when I think of my son - and when do I forget?

It breaks my heart to think that my handsome, well-groomed son who took such pride in his appearance does not even have clothes to wear. It breaks my heart that he has not had a comb to brush his hair in three years.

He told me how sad he was to see that his hair had turned grey from all the stress.

Worst of all, it breaks my heart when I think of his milky white eye which has been blinded so deliberately and callously by the American guards.

My late husband was so determined that Omar did not lose his eye when he was accidentally poked in the eye by another child as a small boy.

The advice in Libya was to remove Omar's eye but my husband refused and took Omar to Switzerland as it had the most advanced eye treatment at the time.

Omar underwent extensive and repeated treatment and numerous surgeries to ensure that he kept his eye functioning as well as possible.

He has had to visit his eye doctor every year since then to receive painful laser treatment.

Alas, all that effort, pain and money has been completely destroyed in such a brutal way.

Sometimes I cannot tolerate staying in the house because of his absence from me as he was my best companion.

How can I tolerate seeing the room of my dear son closed and empty, so empty of my beloved son?

He was my cheerful, vivacious son who never left me alone particularly in the absence of his brothers.

However, now I only have his shadow in my imagination.

I am absent-minded and distraught and every place becomes narrow for me whenever I remember him which is all the time.

He has been in this cursed jail for so many years in conditions which are not even fit for animals.

I pray to Allah during every prayer that he is released and that he finds people who treat him kindly and compassionately. My heart is ruptured with sadness.

I swear that if I could express what I feel properly even dozens of pages would not be sufficient. But this is all I could express.

So what shall I say and what do I say when his little son Suleiman comes to me and asks me: "Where is my daddy? Where is my daddy and when is he coming so I can meet him?"

When he asks me, I feel the world is pulled from under my feet.

I pray to Allah that he comes back to me and to his son soon before I die so that I can feel happy and embrace him while he is in a good condition. Every day I wait for a letter or some news from him but they are so hard to come by.

My anxious feeling chokes me up as I wait for the arrival of anything from him that comforts me.

Even when I receive a letter from him, I find half or more of the letter erased.

They have begrudged me even the pleasure of hearing his news but Allah never neglects those who are in his custody.

I swear by Allah that my son is innocent of all these charges. Omar loves all people and loves helping people.

Have mercy on those on Earth and God will have mercy on you.