A Chinese firm constructing a cement factory in Mozambique's capital, Maputo, has been confining about 60 local workers on the construction site since March.
A company representative says the decision was taken to prevent possible transmission of coronavirus from the workers to their employer.
The Salamanga cement factory is being constructed in Matutuone district in Maputo province.
The decision has kept the workers away from their families.
Lawyer Paulino Cossa says this is violating local labour laws.
A company representative has promised to release the workers next week.