The miners, for the first time, have revealed some of their innermost thoughts and fears in an exclusive TV interview with Bob Simon in a 60-minute report to be telecasted on CBS channel this Sunday.

Trapped half a mile below the surface in sweltering heat and cramped conditions, the Chilean miners' mental faculties were stretched to the limit, the Daily Mail reported Saturday.

Crippling doubts seeped into the mind over whether they would ever see daylight and their loved ones again as they lived out one of the most astonishing stories of human endurance ever.

Living on meagre rations, with survival instincts kicking in, it's no surprise that thoughts and discussion turned to death - and how to keep it at bay.

The men had been beneath ground for more than a fortnight before any sign came from the surface.

By that stage, though, they were rationing an inadequate emergency food supply, down to one can of tuna and eating just one teaspoon each every 48 hours.

In an upcoming book by Jonathan Franklin entitled 'los 33' ('33 Men'), he recalls one of the survivors' joking tone when he suggested that if he died in his sleep, he would be having 'breakfast, lunch and dinner'.

It was no joke, there was no more food. But how long before cannibalism became a very realistic option?

"I would say five or 10 days," says Mario Sepulveda, who became the face of the rescue effort with regular appearances on the camera that was forced through from above. He is now on heavy medication.

"Food or no food, I was going to get out of there...I had to think about which miner was going to collapse first and then I started thinking about how I was going to eat him...I wasn't embarrassed, I wasn't scared."

Franklin adds: "[Miners] told me they had a pot and a saw ready."