A Scotland Yard riot squad officer filmed knocking Ian Tomlinson to the ground will be told later if he faces prosecution over his death.
Keir Starmer, Director of Public Prosecutions, will reveal whether the officer has a case to answer over the G20 protest clash.
The officer, a member of the force's controversial territorial support group, was caught on camera pushing the newspaper seller to the ground.
Mr Tomlinson, 47, died from internal bleeding after collapsing a short distance away in the City of London on April 1, 2009. The officer, who remains suspended from duty, could be charged with manslaughter, assault, misconduct or told no further action will be taken.
Mr Tomlinson's death became global news after amateur video evidence emerged that challenged the original official version of events.
Police told his widow and nine children he died of a heart attack after being caught up in crowded streets around the protests. But the footage showed Mr Tomlinson being struck from behind by a baton and shoved to the ground by an officer in protective clothing.