Adjoa Nyenyanu was seven when her mother sold her and her three younger siblings for about US$60 to work for strangers in fishing villages along Ghana's Lake Volta.

"My mother called me one night and told me she wanted me to go to school but she had no money," Adjoa said. "She said a rich friend of hers will be coming over the next morning for us. She promised the woman will put us in school if I agree to go with her."

For the next five years, Adjoa spent her days diving into Lake Volta to collect fishing nets. Their bosses fed her and her siblings just once a day.

Adjoa's mother, Abena Nyenyanu, said she was given 600,000 cedis ($64) for her four children, but told she would receive about double that amount in later payments.

At the time Abena was selling porridge to support her family, making at best about 30,000 cedis ($4) a day.

"I was in great need. We agreed [the buyers] could have them for five years with regular visits from me but I never saw them till today. I regret what I did and remember crying without control when they left. I am very sorry. I just ask for their forgiveness."

Adjoa said she lived in constant fear. "We are forced to go under the water to remove nets that had been cast the previous day," Adjoa said. "Any time [our boss] faulted us she beat us with a tree stump."

Adjoa and her siblings were reunited with their mother on 15 May as part of an International Organisation for Migration reunification project in Ghana. They had been away for five years.