Friends and family of Michael Famodun stood outside Avondale police station yesterday demanding justice.
They carried placards saying "New Zealand police stop assaulting immigrants now" and "The police should protect us and not kill us".
Mr Famodun's sister, Adekunbi Schwan, held a sign saying her brother died after being assaulted
by an off-duty police officer.
Mr Famodun's family say police are covering up his death and have refused requests for information about the officer.
"They shouldn't protect him." Mr Famodun, who suffered from the blood disorder sickle cell disease, died on February 22 from a massive brain haemorrhage.
He wrote to the Police Complaints Authority in November alleging an off-duty police officer had slammed his head into a car head-rest during an altercation in a Lynfield supermarket carpark earlier in the month.
His family believe the blow began the haemorrhage.
In his letter to police, Mr Famodun said he was on his way home from Auckland City Hospital when the alleged assault occurred.
He said he had been discharged from the hospital after a brief relapse and was still wearing pyjamas and a hospital bracelet.
His cousin picked him up and they stopped at the supermarket to withdraw some money.
They parked in a disabled carpark but were asked to move by a supermarket attendant. Soon after, the off-duty officer approached.
Mr Famodun claimed the officer got angry and tried to grab the keys as Mr Famodun went to move the car.
"He then shoved my right shoulder back into the car seat so hard that the key chain broke and my head slammed into the head rest," he wrote.
"I let out a scream from the pain."
Mr Famodun, who was born in Nigeria, said he then began to have a seizure. An ambulance was called and he returned to hospital.
He suspected the attack was racist.
"I cannot help but wonder if my race had something to do with this irate behaviour and unprovoked attack," he wrote.
He asked police to reimburse him for the ambulance bill and to discipline the officer.
