A documentary was screened on child poverty in New Zealand showing the stark reality of life for many children and their families in the country.

Wellington documentary maker Bryan Bruce, who spent two years researching poverty, said that more than 100 New Zealand children who died last year would have survived had they been born in Japan, Sweden or the Czech Republic.

As part of the study, Bruce visited Sweden, which was once considered similar to New Zealand, and found that children there received free health care, were provided a free meal a day at school and were free from diseases associated with poverty.

In the two years he spent researching the topic, he visited schools, doctors and low-income families in eastern Porirua. Diseases like rheumatic fever, skin infections and respiratory illnesses spread quickly in the damp and overcrowded conditions.

Bruce was calling for politicians to work out a long-term policy for the health of children. If you want to long-term change poverty and children in the underclass, there are two things you have to do: move more people off welfare into work, and make sure you have a world-class education system, Prime Minister John Key told Radio New Zealand.

New Zealand ranks second to last in child health and safety rankings of 30 OECD countries, with only Turkey having a worse record.