From chains to scarred backs, sensationalised images used to raise awareness of modern slavery risk doing more harm than good because they misrepresent the problem, researchers said on Monday.

In fact, most modern slavery networks rely more on psychological methods of coercion than on physical violence or restraint, according to a study by the University of Nottingham’s Rights Lab, which researches the global problem.

Such images also risk re-traumatising survivors, said the study, released on the International Day for the Abolition of Slavery on Monday.

Author Emily Brady said misrepresentations of modern slavery hampered efforts to educate the public on what to look out for.

“All they will be seeing are victims who are physically restrained or hunched over a bed or table, often holding their face in their hands to signify distress,” said Brady, a research associate with the Rights Lab.

“Over time these images can also make people less sensitive to the harm endured by enslaved people because they become the new norm,” she added, calling for survivors to be more involved in selecting images to avoid potentially harmful stereotypes.

The study, Photographing Modern Slavery, looked at common themes in images of modern slavery used in government and charity reports, including the Walk Free Foundation, the Australia-based group behind the Global Slavery Index.

More than 40 million people have been estimated to be captive in modern slavery, which includes forced labour and forced marriage, according to Walk Free and the International Labour Organization.

Misrepresentation could also impact victims’ access to help if their experiences do not match the popular perception of what slavery looks like, said Joanna Ewart-James, executive director of the anti-slavery organisation Freedom United.

The organisation runs a campaign called My Story, My Dignity, which lobbies for survivors’ right to privacy and accurate representation.

“It is incredibly traumatic for people to have their stories misrepresented,” Ewart-James told the Thomson Reuters Foundation.

“When campaigns are led by people who do not really understand what modern slavery is, agency is taken away from victims rather than empowering them.”