Hillsborough investigators have identified 23 criminal suspects over the disaster which left 96 people dead, a spokesman for the two criminal investigations into it has said.
The Crown Prosecution Service (CPS) will now study files relating to the 1989 disaster.
Fifteen of the suspects relate to the Operation Resolve investigation into the causes of the disaster, while eight relate to the Independent Police Complaints Commission's (IPCC) probe into the alleged cover-up following the tragedy, in which 96 Liverpool FC fans died.
It came as the police watchdog's deputy chairman said investigators had looked for the "controlling minds" in an alleged cover up into what happened.
Rachel Cerfontyne said: "We have always said what we want to do was cast the net wide but actually what we've been looking for is the controlling minds.
"If there was a cover-up, and remember at this stage it's allegations of a cover up, then what we wanted to understand was who was behind that, who was making the decisions, who was giving the instructions and that is what we've been focusing on in the evidence gathering to submit to the Crown Prosecution Service."
The IPCC's eight suspects are all retired police officers, who served in either South Yorkshire Police or West Midlands Police - the force which investigated the disaster.
The watchdog has been considering offences including perverting the course of justice, conspiracy to pervert the course of justice and misconduct in public office.
Assistant commissioner Robert Beckley, head of Operation Resolve, said the 15 suspects identified by that operation included organisations, police officers and civilians.
He said investigators aimed to be "impartial and unbiased" in their work.
He said: " They've worked through the evidence and in their judgment, in our judgment, there's sufficient evidence for these 15 people and organisations."
Operation Resolve investigators considered offences of gross negligence manslaughter, perverting the course of justice, misconduct in public office and offences under the Safety of Sports Grounds Act 1975 and Health and Safety at Work legislation.
Ms Cerfontyne said she understood families of the victims may be disappointed after the watchdog decided not to investigate suspended South Yorkshire chief constable David Crompton.