A public meeting has been held in Luton to discuss allegations that a man with severe autism was beaten in the street by two Bedfordshire Police officers.
The family of Faruk Ali say he was helping binmen outside his Luton home when the police officers carried out an unprovoked attack.
They say he has been left "scared" and "agitated" by what happened.
Bedfordshire Police says it is investigating and has placed the officers on "restricted duties".
According to his family, Mr Ali likes routine and helps the binmen every Thursday.
They say he was doing this on 20 February when two officers got out of a police car and grabbed him, saying he looked suspicious.
Musthafa Hussain told BBC Look East he saw the incident.
"They dragged him, they punched him, they held him hard," he said. "It was outrageous."
A statement from Bedfordshire Police said the force was "sorry for the distress Mr Ali and his family feel regarding the actions officers took due to their concerns for Mr Ali's wellbeing".
"This incident is being taken seriously and an investigation has been launched by the Beds, Cambs and Herts Professional Standards Department which will be supervised by the IPCC."
The meeting at Bury Park Community Centre, organised by Mr Ali's family, was attended by Assistant Chief Constable Nigel Trippett, of Bedfordshire Police.