Ninh Pham (60) had been a fisherman in rural Vietnam before he came to Europe in search of his missing daughter.
In 2006 he was living in the Vietnamese community in Birmingham when he was offered work in Ireland. Pham accepted and was smuggled into the country in the back of a truck.
His employers took his travel documents and passport before bringing him to a five-bedroom detached premises in Templeogue, Dublin, which was being rented though a letting agency.
The entire house had been converted for cannabis growing. Sophisticated heating and lighting systems were in place and the attic was converted to accommodate ventilation units.
Pham lived on the floor of the sitting room. His job was to water the plants and ensure equipment was kept in working order. Once a week he was allowed to leave the house to buy food. He was told he would get his passport back and be allowed to leave when the cannabis was harvested.
In December 2010 gardaí raided the house, where they found Pham and 600 cannabis plants in various stages of growth. Pham co-operated with gardaí and pleaded guilty at the first opportunity. He said he did not know cannabis was illegal in Ireland.
When his case came before Dublin Circuit Criminal Court, his barrister read out a letter from Pham apologising to the people of Ireland. His counsel submitted that Pham was in poor health and just wanted to return home.
Judge Martin Nolan accepted Pham had been forced to grow the plants. He jailed him for 1½ years.