By Will Ross
BBC News, Accra
Police in Ghana have arrested four people accused of trafficking children and are pursuing two others who are apparently on the run.
They are accused of sending children as young as five from the coast to work in fishing communities in Yeji towards the north of Lake Volta.
It is not uncommon for Ghanaian families to send their young children to work with fishermen.
Poverty drives the practice which has been going on for generations.
Parents struggling to bring up their children would typically receive about $50 (£25) in return for sending them away for three years - which some view as an apprenticeship.
The children are used for diving under water to untangle the nets or for picking the fish from fine nets.
Joseph Rispoli of the International Organisation For Migration (IOM) said the work is often dangerous.
"Their hands, especially the girls', are not as coarse as the fishermen's hands, so they actually use those little girls to be able to extract the fish from these winch nets.
"They even cut their hands open on the scales sometimes."
Last month a four-year-old boy drowned in Yeji - a tragedy which helped the police uncover the trafficking network.
Two years after a human-trafficking law came into force, the IOM sees the arrests as a major breakthrough and a sign that the issue is now being taken seriously.
The organisation has identified about 100 children who have been trafficked to another area on Lake Volta.
But because of a lack of funds it can only rescue and reintegrate one third of those children.