Around 7.30am on Monday (August 23), police were called to Pitt Street in Heywood following reports of a collision between a pedestrian and a silver Vauxhall Astra car-derived van.
A man in his 50s was taken to hospital but has since died as a result of his injuries.
A 41-year-old man was arrested on suspicion of driving under the influence of drugs, and causing serious injury by dangerous driving.
He has since been released under investigation.
Police Constable Suzanne Keenan, of GMP's Serious Collision Investigation Unit, said: "A man has very tragically died as a result of his injuries following this collision and as such, we are continuing to appeal to the public for information.
"This collision happened in the build up to rush hour so we are confident that there will be a number of people who may have seen this incident or have dash cam footage.
"Any information you have could help us provide his loved ones with the answers they deserve."
Anyone with any information or dash cam footage of the incident is being urged to contact police as soon as possible, either through LiveChat on the website: www.gmp.police.uk or call 0161 856 4741 quoting incident number 679 of 23/08/2021.
Alternatively call the independent charity Crimestoppers anonymously on 0800 555 111.
