A man has died days after becoming unresponsive while in police custody in Melbourne, sparking an investigation by the homicide squad.

Police were called in to assist paramedics who were treating the man at the corner of Sydney Rd and Albert St in Brunswick about 9.30pm on Friday, June 6.

It was unclear what led to the 43-year-old man needing treatment, however, he became agitated and aggressive, police said.

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The man started to walk away on Sydney Rd when he was arrested and put into an ambulance but became unresponsive on the way to hospital.

Police said the man died in hospital on Wednesday night.

“Detectives from the Homicide Squad will investigate the incident with oversight from Professional Standards Command, as per standard practice when someone dies after being taken into police custody,” police said.

Anyone with information is urged to contact Crime Stoppers.

On Saturday, a 68-year-old man died while in police custody in a Northern Territory hospital, days after he was arrested on May 30 allegedly attempting to board a flight while intoxicated.

Two weeks ago, a 24-year-old man died after he was restrained by plain clothed police officers in an Alice Springs supermarket after allegedly assaulting a security guard.