Evidence on 23 people and organisations linked to the 1989 Hillsborough disaster has been handed to prosecutors, it has been revealed.

The Independent Police Complaints Commission (IPCC) said files on the unnamed 23 have been passed to the Crown Prosecution Service (CPS).

An inquest jury last year surrounding the tragedy that killed 96 Liverpool fans found the former chief superintendent of South Yorkshire Police, David Duckenfield, responsible for manslaughter by gross negligence.

The announcement today spells the end of four years of investigation into what amounts to a report more than 35 million words long.

Former South Yorkshire Police chief superintendent David Duckenfield told the Hillsborough inquest his failure to close the tunnel caused the deaths of 96 Liverpool fans AFP/Getty (AFP/Getty)

IPCC Deputy Chair Rachel Cerfontyne said: “These criminal investigations into the circumstances surrounding the Hillsborough disaster are the largest investigations into alleged police wrongdoing ever undertaken in England and Wales.

“Conducting an inquiry of this scale and complexity, while supporting the longest running inquests in British legal history, has been a significant undertaking for the IPCC. Our criminal investigation has now substantially concluded.”

Of the 23 suspects, 15 relate to Operation Resolve, which probed the cause of the disaster.

It says potential offences include gross negligence manslaughter, perverting the course of justice, misconduct in public office, offences under the Safety of Sports Ground Act 1975, and offences under Health and Safety at Work legislation.

The eight individuals picked out by the IPCC, which examined South Yorkshire Police, West Midlands Police and claims of an alleged cover-up, similarly single out potential offences of perverting the course of justice, conspiracy to pervert the course of justice, and misconduct in public office.

Andy Burnham's tribute to Hillsborough victims

The IPCC, which says its probe has cost £45m to date, said more than 170 allegations of police misconduct continue to be investigated by its team and that the referrals to the CPS do not necessarily lead to charges.

Sue Hemming, head of CPS Special Crime and Counter Terrorism Division, said: “Having received files from both Hillsborough investigations, we will now assess these in order to determine whether we have sufficient material on which to make charging decisions. Charging decisions will be based on the tests set out in the Code for Crown Prosecutors.”

Hillsborough families react to inquest conclusions Show all 10 1 /10 Hillsborough families react to inquest conclusions Hillsborough families react to inquest conclusions Relatives react after the jury delivered its verdict at the new inquests into the Hillsborough disaster, in Warrington Reuters Hillsborough families react to inquest conclusions Relatives of those who died in the Hillsborough disaster celebrate outside the Hillsborough Inquest in Warrington PA Hillsborough families react to inquest conclusions Margaret Aspinall holds a banner after the jury delivered its verdict at the new inquests into the Hillsborough disaster Reuters Hillsborough families react to inquest conclusions Relatives of the Hillsborough sing 'You'll never walk alone' as they depart Birchwood Park after hearing the conclusions of the Hillsborough inquest Getty Images Hillsborough families react to inquest conclusions Relatives of Hillsborough victims show their emotions as they depart Birchwood Park after hearing the conclusions of the Hillsborough inquest Getty Images Hillsborough families react to inquest conclusions Relatives of Hillsborough victims hug as they depart Birchwood Park after hearing the conclusions of the Hillsborough inquest in Warrington Getty Images Hillsborough families react to inquest conclusions Margaret Aspinall (C), whose son James died in the 1989 Hillsborough disaster, makes a statement following the conclusion of the inquest into the 1989 Hillsborough disaster Getty Images Hillsborough families react to inquest conclusions Relatives sing "You'll never walk alone" after the jury delivered its verdict at the new inquests into the Hillsborough disaster Reuters Hillsborough families react to inquest conclusions Relatives of Hillsborough victims hold up banners as they depart Birchwood Park after hearing the conclusions of the Hillsborough inquest Getty Images Hillsborough families react to inquest conclusions Donna Miller (R), sister of Hillsborough victim Paul Carlile holds up a banner as relatives depart Birchwood Park after hearing the conclusions of the Hillsborough inquest in Warrington Getty Images

Assistant Commissioner Robert Beckley, Officer in Overall Command of Operation Resolve, said: “Our task has been to investigate whether any individual or organisation is criminally culpable for their role either in the planning and preparation for the match or on the day of the game itself.

“The extensive file we have submitted, which contains over 35 million words, reflects four years of intense work from my team. As well as conducting a criminal investigation, for three years we also supported the coronial process in providing the coroner with thousands of documents, witness statements and reports to assist him in conducting the inquests.”

The IPCC also said 4,500 witness statements had been taken and over 1,200 interviewed.

Its work has also surrounded allegations that misleading information was passed to media and politicians, that campaigners and families were spied on, and surrounding Sir Norman Bettison’s appointment at Merseyside Police as chief constable.

A 1980s computer, 167 floppy discs, a leatherbound book of SYP policies, 5,500 SYP pocket notebooks and 19,000 images were also seized.

Hillsborough Family Support Group president Trevor Hicks, whose two teenage daughters Sarah and Vicki were killed at the FA Cup semi-final match, has told The Guardian: “My view is that it is better to go forward with 23 cases which are solid than more which might be lost, particularly as some of these potential charges are very serious.