Slave labour, beatings, sexual abuse, fear and isolation were the norm for thousands of “Verdingkinder”, or"discarded children", who were given away or sold as cheap labour until the 1950s.

Historian Marco Leuenberger told swissinfo that the time has come for reappraisal of this dark episode.

Leuenberger was ten years old when his father first told him of his childhood as a discarded child. Also aged ten, his father had to endure the daily grind of getting up at 5am and working until late into the night.

Inspired by his father and thousands of children like him, Leuenberger in 1991 embarked on a huge research project to explore this dark chapter in Switzerland's history.

The discarded children were usually orphans, illegitimate or came from the poorest families and they were either given away or sold to farmers.

“Most of these children were used as cheap labour, exploited physically or even sexually abused,” Leuenberger concludes in his study.

Leuenberger and other historians are calling for a nationwide research project to be carried out into the trade in “Verdingkinder”, while many of these former child labourers are still alive.

swissinfo: Were children given away or sold throughout Switzerland?

Marco Leuenberger: Yes, especially in German-speaking Switzerland in the Protestant cantons, though also in Catholic areas. It also happened in [French-speaking] canton Vaud. It is also known that children from [Italian-speaking] canton Ticino were sent to work as chimney sweeps in northern Italy.

swissinfo: How many of these ‘Verdingkinder' were there?

M.L.: For years, the trade involved more than 10,000 children [every year]. But it's very difficult to come up with an estimate because there is no evidence available prior to 1820. There were also lots of children who were traded without the knowledge of the local authorities.

swissinfo: How did Swiss authorities manage this child trade?

M.L.: Poor families were forced to register with their local authority every year. It was then decided whether all the family members were [adequately] provided for. Authorities in the 19th century had the right to separate the poorest families.

There were no criteria that [farmers] had to fulfil to receive a “Verdingkind”. They only had to prove that they needed more cheap workers.