Report by ITV News Correspondent Damon Green.
Families of victims of the Hillsborough disaster are pursuing legal action against South Yorkshire and West Midlands Police.
The case, pursued by families of the 96 fans who died, accuses the police of a "systematic cover up" and "abuse on an industrial scale".
This week an inquest jury delivered a finding of "unlawful killing" over the fatal incident on April 15, 1989.
On Wednesday, the Chief Constable of South Yorkshire Police David Crompton was suspended, a move welcomed by the families of Hillsborough victims.
A day later, Chief Constable Crompton's interim replacement Dawn Copley stepped down after just 24 hours in the post, amid reports she is being investigated over her conduct within Greater Manchester Police.
The legal case was issued at the High Court last year but publication of the claim was prevented until after the inquest concluded.
The action, brought by law firm Saunders Law on behalf of hundreds of those affected by the disaster, is for "misfeasance in public office".
The firm said in a statement: "In addition to the police wrongdoing that caused the deaths, there is evidence of the systematic cover up intended to transfer the blame for what happened from South Yorkshire Police to the innocent, by spreading lies, doctoring evidence, pressurising witnesses and suppressing the truth.
"The evidence points to abuse on an industrial scale by both South Yorkshire and West Midlands Police, beyond any 'one bad apple' analysis.
"In addition to actions by individuals, the evidence suggests institutional misfeasance by these bodies directed against our clients and the fans generally."
The news of the action comes after it emerged retired officers from South Yorkshire Police were told to be proud of their work in the 1980s, in a message mistakenly made public on a website in the wake of the Hillsborough inquest findings.