The number of potential trafficking and modern slavery victims reported to the authorities has risen by 36% in a year, National Crime Agency figures show.
Last year, 6,993 potential victims were referred into the government system, up from 5,142 in 2017 and 3,804 in 2016.
But the Human Trafficking Foundation told the Victoria Derbyshire Programme the system is failing to provide long-term support for victims.
The Home Office says its work ensures thousands of people receive support.
Potential victims are reported to the National Referral Mechanism (NRM), which is designed to identify and support victims, while making the prosecution of traffickers easier.
Once a victim has signed the form and entered the NRM, the Home Office and the UK Human Trafficking Centre must decide whether to class a person a victim of slavery within 45 days. Once a victim is in the system they can access legal advice, accommodation, protection and support.
Tamara Barnett from the Human Trafficking Foundation said a lot of survivors are sent home, or disappear ‘into the ether, back into destitution’.
“We’ve heard from police officers who have referred people into the NRM repeatedly because each time they leave the NRM they’re becoming destitute, being re-trafficked, and the police are identifying them again.
“The NRM just isn’t working on that long-term scale.”