Auckland City Missioner Diane Robertson says many young homeless people are on the streets because it's safer than living with their family.
Ms Robertson says many homeless people live rough to escape domestic violence and sexual abuse.
However, once people are on the street, she says it can be hard to shift them into regular housing because they find it hard to trust people.
Social Development Minister Paula Bennett says the Government is concerned about research that may indicate a homeless population of 20,000 across New Zealand.
She says agencies dealing with homeless people need to co-operate better.