Prosecutors have completed a review of the document and passed their findings back to the London force.
Relatives of the dead man have been campaigning to obtain a secret internal review of the killing for many years.
Last year Metropolitan Police Commissioner Sir Paul Stephenson said he was willing to publish the document but only after it had been checked by solicitors.
A CPS spokeswoman confirmed officials have completed their work and given their findings back to officers. It is understood a copy of the report has already been passed to solicitors representing Mr Peach's partner, Celia Stubbs.
The decision to publish was made after public pressure to reveal the almost forgotten review in the months after the death of Ian Tomlinson during G20 protests.
A shadow hung over the death of Mr Peach, 33, since he was hit over the head at a demonstration against the National Front in Southall, west London, in 1979.
Members of the force's Special Patrol Group were suspected of hitting him with a rubberised police radio or a lead-filled cosh.
The report written by Commander John Cass, a former senior officer at the Met's internal complaints department, examined his death. He is believed to have recommended the prosecution of police officers, although no charges were ever brought.
Speaking last June, Sir Paul said the report should be published, possibly by the end of the year, with some details censored. The Metropolitan Police Authority unanimously supported a decision to review the documents with a view to publishing them.
Daily Express
