NANNING -- A city in South China is offering free DNA tests to low-income families, which will help them register their offspring and receive poverty relief benefits.

The authorities in Yongning District in Nanning city, the capital of Guangxi Zhuang autonomous region, have decided to waive the cost of DNA tests for 500 poor and unregistered people so that they can register for a resident permit, known as a "hukou," and qualify for financial and social assistance.

In China couples must register their marriage with their local civil affairs agency, however, in some rural and under-developed areas this is not always followed. This means that their children, who are often born outside hospitals and clinics, are unregistered and, therefore, unable to access many social benefits, including poverty relief.

A DNA test, which can prove the biological link between children and their parents, is the first step toward getting these unregistered people a hukou.

Children must have a hukou to enroll into public schools and, later, it is also a required document for employment.