The illegal sale of children makes up more than half of all the cases of human trafficking around the world, according to recent estimates.

Traditionally it has involved the exploitation of children in poorer nations, but an Al Jazeera investigation has found that it is also happening in developed countries, such as South Korea.

For four months, Al Jazeera surfed community boards on popular Korean internet sites, and found an underground trade where pregnant women can sell their unborn children.

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The few cases that have surfaced have alarmed the government so much that it is believed to have formed a special task force to bring human-trafficking laws up to date, Al Jazeera's Steve Chao says.

One of the challenges is how to give authorities the power to better police the murky world of the internet.

Twenty years ago the United Nations adopted the Convention of the Rights of the Child. The CRC or UNCRC, sets out the civil, political, economic, social and cultural rights of children.

As of December 2008, 193 signatories had ratified it, including every member of the UN except the US and Somalia.

The treaty restricts the involvement of children in military conflicts and prohibits the sale of children, child prostitution and child pornography.

The UNCRC has been used as a blueprint for child protection legislation around the world.

However, the treaty's promise to protect children has not always been kept.

Onus on government

Lisa Laumann, from the Save the Children charity, says it is up to both the government and the community to protect children.

"Intergovernmental organisations like the United Nations provide the framework around which governments can come together to agree on what good practice is and how governments should behave legally on behalf of their citizens," she told Al Jazeera.

"But it's up to the governments themselves to draft that legislation, develop the systems and institutions that guarantee those rights.

"There also has to be an effort made to help communities, families and children themselves, to understand what rights mean for them and how they can support them."

Source: Al Jazeera