Officers were called around 9.55am on Sunday 20 March 2022 to Church Road, Urmston to a report of a collision involving a motorbike.
Enquiries have since established that the motorbike - a Yahama MT-07 ABS - had been travelling along the road in tandem with two other motorbikes when the rider fell from the vehicle into the carriageway.
An investigation is ongoing to determine how he came to fall but at this stage it is believed he may have been in collision with another rider in tandem.
The rider - a 33-year-old man - was taken to hospital but has since sadly died as a result of his injuries.
His next of kin have been informed.
Sergeant Matt Waggett of GMP's Serious Collision Investigation Unit said: "A man has very sadly died as a result of this collision and our thoughts are with his family and loved ones at this incredibly difficult time.
"No arrests have been made at this stage of the investigation but we are currently appealing for anyone who may have been in the area at the time, or witnessed the three motorcycles or the collision, to come forward and assist us with our investigation.
"We are particularly keen to speak to anyone who may have dash-cam, mobile phone or CCTV footage so I would encourage anyone who was in the area to check their devices as they may have unknowingly captured vital evidence."
Anyone with information should contact our Serious Collision Investigation Unit on 0161 856 4741 or 101 quoting incident 939 of 20/03/22.
Alternatively, details can be passed via our LiveChat at www.gmp.police.uk or via the independent charity Crimestoppers on 0800 555 111.