Edir Frederico Da Costa was in a car with two others when it was stopped by officers from the Metropolitan Police in East London.
His father claims police suspected the car had been involved in a robbery, but his son resisted after stating his innocence.
Da Costa died on Wednesday, six days after his arrest.
But a postmortem examination on Thursday concluded there were no injuries to suggest severe force was used, though an internal police inquiry has been launched.
"Corrupt, corrupt from the bottom to the top - and you tell me it's the law"
A song by the Levellers sprang to mind.
When will the police people get it - they were once one of us!
Love Steve
By Oldschool Returns from Alentejo on 25 Jun 2017, 11:03