The operation was set up in the wake of the 2014 Jay Report, which laid bare the shocking scale of exploitation in the South Yorkshire town between 1997 and 2013, as well as the failure of police and social services to intervene.
Latest figures show investigators are working to trace a horrifying total of 426 grooming gang members who abused an estimated 1,500 victims in Rotherham over the 16 year period.
Officers have engaged with over 410 victims and survivors and have arrested or interviewed by appointment 94 suspects, meaning this is the largest law enforcement investigation into non-familial CSE (child sexual abuse and exploitation) ever undertaken in the UK.
The operation could cost £90m if the Government continues its current funding until 2024.
Paul Williamson, senior investigating officer, said: “Our number one priority is to focus on the victims and survivors, and that will never change.
“The challenges are huge, and this is why we need more people to join us so we can do more and do it more quickly.”
It is currently running 22 separate investigations under Operation Stovewood.
An NCA spokeswoman said: “This is the largest single CSE investigation ongoing in the UK. lt is likely to go on for a number of years..
"Underneath the Stovewood umbrella have a number of ongoing sub investigations. These are looking at different individuals and victims. You can not put it into one big operation because it is just too complex a nature.
“It has previously been said the operation could take up to 10 years because of the scale of it and the time it takes each of the investigations.
“The victims were young girls at the time. They are now late twenties and it takes a lot for them to come forward and relive what happened to them. In some cases victims can take a number of years before they can get to the point of giving evidence in court. Others might not be as long, but it is a very complex set of circumstances and you have to go at the pace of the victim.
Up to now there have been seven successful court prosecutions under Operation Stovewood.
In November 2018, seven men were found guilty of 24 sex offences when they abused five girls aged under 16 between 1998 and 2005. They were convicted of charges including rape, procuring a girl under 21 for sexual intercourse and aiding and abetting rape.
The men were jailed for a total of more than 100 years,
Detectives revealed in May this year how they arrested or interviewed 40 people in just two months regarding CSE in Rotherham.
The 38 men and two women were questioned following allegations made by 13 victims about sexual abuse against them.
Read more: CSE victims of Yorkshire grooming gangs should be compensated for official failures – The Yorkshire Post says
Those arrested were aged between 29 and 53 and from Sheffield, Rotherham, Leeds, Dewsbury, and Maidstone in Kent.
All were bailed or released under investigation pending further inquiries.
South Yorkshire Police has welcomed the progress made by the NCA.
Detective Superintendent Shelley Hemsley said: "Operation Stovewood has so far made significant headway in investigating these reports, which has in turn encouraged other victims of non-recent sexual abuse to come forward. From 2015 onwards, we have experienced a significant rise is the reporting of non-recent cases in Rotherham. These are now being investigated by the NCA."