Britain's police watchdog is to interview the officer seen in video footage striking Ian Tomlinson, the man who died during the G20 protests in the City of London last week.
The officer has identified himself to investigators, a spokesman for the Independent Police Complaints Commission (IPCC) said last night.
He was seen apparently hitting the 47-year-old newspaper seller with his baton and pushing him to the ground. Mr Tomlinson later collapsed and died.
The officer, from the Metropolitan Police, will be interviewed by IPCC investigators “as soon as possible”, the spokesman said. There was no indication when this might be.
Scotland Yard said no officers had been suspended over the incident.
Footage shown on Channel 4 news last night showed a riot officer seemingly striking out at Mr Tomlinson with a baton before pushing him to the ground.
Previous footage, obtained by the Guardian, showed Mr Tomlinson being hit and pushed over by a partially-masked officer as he walks away from a police line with his hands in his pockets.
The new footage, taken by a Channel 4 News cameraman, shows an officer apparently striking him left-handed with a baton, then shoving him to the ground.
Earlier the IPCC said a number of officers captured on camera when Mr Tomlinson was struck had yet to come forward.
The watchdog has ordered a second post-mortem examination in a bid to determine if there was any external factor behind his fatal heart attack.
The video prompted Mr Tomlinson’s stepson to demand answers from police as he called for the officer responsible to be “pulled in”.
Paul King, 26, said his father left work selling newspapers at Monument Tube station at about 7pm but was prevented from getting home by police barricades.
Speaking to The Guardian, Mr Tomlinson’s widow Julia described her anguish after watching the video.
“When I close my eyes, I can’t stop the video playing in my head. How he slams to the floor. How the officers don’t go to his help. It is disgusting,” she said.