At around 12pm on Monday a silver Audi A3 and a white van were involved in a collision on Halliwell Road.
The driver of the Audi fled the scene before being detained by a member of the public nearby on Rushey Fold Lane.
A short time later a second man – who was driving a silver Seat Ibiza – arrived at the scene and threatened the member of the public with a knife before allowing the Audi driver into his car.
The Seat Ibiza then left the scene.
The driver of the Audi A3 is described as Asian, aged between 19 – 24-years-old, around 6ft tall and of slim build with short dark hair. He was clean shaven and wearing a red puffer jacket with black jeans.
The driver of the Seat Ibiza is described as mixed race, aged 20-25-years-old and had a scar under his right eye.
Investigators are appealing for information and want to speak to anyone who saw the incident take place or the cars in the area before the collision.
Officers are particularly keen to speak to any members of the public who may have dash cam footage and are urging people who were in the area to check their dash cams to see if any of the incidents were captured.
Details can be passed on to police by calling 0161 856 5508 quoting incident number 0875 of 01/04/19.
Alternatively, information can be given anonymously to the independent charity Crimestoppers on 0800 555 111.