Aninternal police investigation is under way after one protester alleged officers pulled him from his wheelchair.
Jody McIntyre, who has cerebral palsy, is considering a formal complaint.
A video of Mr McIntyre apparently being wrenched from his wheelchair and onto the street by police has appeared on Youtube.
He told the BBC that one of the police officers came running over towards him, tipped him out of his wheelchair onto the road and then dragged him by his arms from the middle over to the side of the road.
“There is no way you can classify me as a physical threat when I am sitting in my wheelchair not doing anything,” he said.
Scotland Yard said the issue had been referred to the Directorate of Professional Standards, an internal body that examines officers’ conduct.
