The campaign group is using this historic event to raise awareness about the people who are coerced into coming to the UK on the promise of a job and a better life, only to find themselves trapped in exploitation.
Stop the Traffik has placed giant gift boxes around the city centre for members of the public to explore.
The boxes are pieces of street art but upon closer inspection they display more information about human trafficking and how to tackle it.
Stop the Traffik collaborated with the United Nations Global Initiative to Fight Human Trafficking (UN GIFT) on the boxes.
Three hundred volunteers also gave their time to make the project possible.
Stop the Traffik said on its website: "It is our collective responsibility to use the Games as a platform to alert the world to the reality of this tragic crime; to inspire the millions of visitors gathered in London over the coming weeks - residents from thousands of communities all over the globe – to become aware of the problem and take action to stop human trafficking."
The GIFT boxes will be moving around the capital to various locations. You can track their whereabouts on the GIFT box map: ungiftbox.org/boxes