Some 90 police pocket notebooks that could provide vital information about the 1989 Hillsborough disaster have been recovered by investigators.
Retired and serving officers handed in the notebooks to South Yorkshire Police, The Independent Police Complaints Commission (IPCC) revealed.
ITV News Correspondent Damon Green reports:
Boxes of notebooks and other documents that cover the period of the disaster were also found by the force and could hold important details.
The IPCC revealed last month that at least one officer made a note of what happened at Hillsborough, against instructions, and none of the previous inquiries had recovered any such notebooks.
The 1989 disaster, that claimed the lives of 96 Liverpool fans, is now at the centre of the biggest ever inquiry into police conduct in the UK.
Director of Public Prosecutions Keir Starmer QC told ITV News he will meet with the families of Hillsborough victims on Friday after they voiced their concerns over the slow progress of the inquiry into the 1989 disaster.
He added that he was "well aware" of their concerns.
Evidence has been uncovered that suggests the statements of 74 more officers might have been changed, and that fans' witness accounts could also have been altered, the IPCC said.
Investigators are set to appeal for witnesses next week in relation to how West Midlands Police ran their inquiry into the handling of the disaster by South Yorkshire Police. Around 12,000 people spoke to West Midlands Police as part of their inquiry.
The appeal is likely to be promoted during Liverpool Football Club's home match on September 21.