It is 8am and the rain is coming down in sheets. The streets are empty except for a dozen women and their pimps – women from some of the world’s poorest regions including Moldova, Romania, West Africa and Southeast Asia. Some are still in their teens.

Not far away are numerous massage parlors and saunas offering women and girls for sale.

This is not Amsterdam or a seedy quarter of one Asia’s megacities. It is Geneva, Switzerland, home to the World Health Organization, the International Committee of the Red Cross and countless other UN bodies and NGOs dedicated to humanitarian causes.

Human trafficking and modern slavery are supposed to be what they are fighting against. Yet here it is happening at scale right under their noses.