An investigation into the police response to widespread child sexual exploitation in Rotherham is nearing its conclusion.
The inquiry into allegations relating to police conduct in relation to the abuse of hundreds of children in Rotherham is the Independent Office for Police Conduct's (IOPC) second biggest-ever operation, after its investigation into the Hillsborough disaster.
But there has been criticism about the length of time the IOPC is taking to conclude the matter, including from South Yorkshire Police and Crime Commissioner Alan Billings.
The IOPC said the Operation Linden was "nearing closure" and that 64 of the 91 independent investigations within it are now complete.
A spokesman said that 13 officers remain under investigation, but he said this figure will continue to fluctuate as inquiries progress.
He also confirmed that the 27 ongoing investigations include the inquiry the IOPC announced last summer into allegations that senior officers failed in their statutory duty to protect children between 1999 and 2011.
The spokesman said that the actions of the senior commanders is continuing to be analysed but no former or current officers have been issued with notices that their conduct is under investigation.
Operation Linden began after the 2014 Jay Report shocked the nation when it highlighted how more than 1,400 children had been subjected to sexual exploitation in the South Yorkshire town between 1997 and 2013.
The report highlighted how police and social workers knew about some of the abuse but failed to respond properly.
Pre-2013 child sexual exploitation in Rotherham is now being investigated by the National Crime Agency, under its huge Operation Stovewood inquiry.
"We are pleased that Operation Linden continues to make good progress.