The UK's first Anti-Slavery Commissioner Kevin Hyland has made Nigeria a high priority, as latest figures reveal a rise in the number potential trafficking victims brought to the UK.
Here are some facts about the issue.
- Hundreds of Nigerians brought into the UK every year for forced labour or prostitution, this includes men, women, and children.
- Latest figures from the National Crime Agency reveal that more than 2,000 potential trafficking victims were referred to the authorities in 2014 - 244 of whom were from Nigeria.
- Nigeria is one of the world's main source countries of human trafficking. It is also the key African source country for women trafficked for the sex trade.
- The country's Edo State is the hub of its trafficking crisis.
- Around half those arrested for trafficking in Edo State are women.
- Italy is the most popular destination for Nigerian trafficking. It is estimated there are as many as 10,000 Nigerian prostitutes.
- Nigeria's National Agency For The Prohibition of Trafficking in Persons (NAPTIP) was set up in 2003.
- To date, NAPTIP have rescued 6000 victims - but in 2014 only 19 traffickers were convicted.
Video report by ITV News presenter Julie Etchingham: