A major inquiry into historic child sex abuse in Rotherham is set to continue for up to seven years with around 600 victims still to be spoken to.
Operation Stovewood was started by the National Crime Agency (NCA) in 2015 after it emerged at least 1,400 children were abused from 1997 to 2013.
So far, 20 people have been convicted, five await trial and 135 arrested.
The agency said inquiries had been restricted by Covid-19 but it was working tirelessly to support victims.
According to NCA analysis, the potential number of abuse victims and survivors stands at just over 1,500.
It said officers had so far engaged with 872 victims and 213 suspects had been indentified.
Based on current information, the NCA said its investigation was „likely to continue for the next five to seven years“.
Phillip Marshall, NCA senior investigating officer, said the coronavirus pandemic had affected the progress of inquiries with officers having to work in line with government restrictions.
„This has not diminished our resolve to protect victims,“ he said.
„We have continued to work tirelessly to support victims, through phone and video conferencing.
„We have since been able to recommence direct interviews.“
South Yorkshire Police asked the NCA to lead an independent investigation following a report by Professor Alexis Jay in 2014 which found the abuse was ignored by agencies.
Mr Marshall said along with Rotherham Council there was ongoing work at various levels to rebuild confidence in agencies to enable more victims to come forward, according to the Local Democracy Reporting Service.
He said: „We have engaged with a vast number of victims, and intend to engage with others, who we would appeal to come forward.
„Victims will be treated with the utmost respect and sensitivity.“