Rev Hyeon Soo Lim appeared at his church in Toronto yesterday, the first Sunday after his release from detention in North Korea, and moved his congregation to tears with his account of his imprisonment.

Pastor Lim, who had made frequent humanitarian visits to the country, was imprisoned two years ago but released suddenly in what he believes was a gesture of goodwill.

Wearing a baggy charcoal-grey suit and speaking in his native tongue of Korean, Lim described a harsh life of labour in solitary confinement, where he was forced to dig holes in frozen ground for two winters.

'The mud was so hard that it took two days to dig one hole, 16 hours,' he told the congregation of several hundred.

'It was incredibly challenging. My upper body was sweating. My fingers and toes were frostbitten.'

He said his health suffered in his first two months at the labour camp, and his weight dropped by 23 kg, but he added that his condition had since improved.

He admitted he suffered from 'overwhelming loneliness' during his captivity as he ate 2,757 meals in isolation and worshipped alone for 130 Sundays, the Globe and Mail reported.

He thanked the Canadian government and the Swedish embassy in Pyongyang for his release.

'It's a miracle for me to be here today,' he told congregants in Korean. 'I always knew Canada was a very warm and compassionate nation, but through my ordeal I really began to grasp that very deeply.'

Before he took the stage to address the congregation, the church sang a hymn he wrote while imprisoned. He denied he ever committed the crimes for which he was jailed, but said he would let the issue remained in the past: 'North Korea has enough problems as is,' said family spokesperson Lisa Pak, who interpreted for him.