A man who died last week had a medical episode "a matter of seconds" after he was handcuffed, according to Victorian Police Chief Commissioner Shane Patton.
The homicide squad is investigating the man's death last Tuesday at Cranbourne, southeast of Melbourne.
A police patrol spotted the 32-year-old man walking in traffic.
He was asked to get off the road but refused and became aggressive towards the officers, police said.
When they tried to arrest him, the man appeared to suffer a medical condition and died at the scene despite resuscitation attempts.
Mr Patton said the circumstances of the death still need to be determined.
"As I understand, there was a foot chase after that man had been causing some trouble in the street," Mr Patton said on Monday.
"He was subsequently handcuffed and as I understand it, he collapsed and was having a medical episode.
"He was un-handcuffed immediately and we're talking a matter of seconds.
"Medical assistance was sought, officers on the scene gave CPR and unfortunately he passed away."
