A man who collided with a bus in Manchester city centre has now died.
Officers are still trying to trace two women who may hold vital clues as to what happened in the moments leading up to the collision.
Shortly after 11.30pm on Saturday 10 September 2011, police were called to Oxford Road at its junction with Chester Street following reports a man had collided with a city-bound double-decker bus.
Officers attended and the man was taken to the Manchester Royal Infirmary, but died on Sunday evening as a result of his injuries.
He has now been named as David Mark Schofield, 21, of Powell Avenue, Hyde.
The bus driver immediately went to David's aid after the collision and later told police he had been approached by two women who told him they believed David had been the victim of a theft moments before the collision.
They told the driver David may have been pursuing a cyclist who stole his mobile phone moments earlier and stepped into the road while chasing the offender.
Officers have been searching through CCTV from the city and have found footage that appears to corroborate what the women told the bus driver.
Police are continuing to appeal for witnesses. Detectives are also appealing for a cyclist wearing a light-coloured hooded top and riding a small, possibly a BMX, bike to come forward.
North Manchester Divisional Commander, Chief Superintendent Russ Jackson said: "Tragically, David's injuries have now proved fatal, and it is now even more important for his family that we establish exactly what happened in the moments leading up to his sad death.
"We have a third-hand account that David was chasing a thief on a pedal cycle who stole his mobile phone - but as yet the two women who told the bus driver this have not come forward. It is therefore absolutely vital we speak to these women so please if you are reading or hearing this, we need to hear from you.
"You are not in any trouble whatsoever - we simply want to know what you saw and help us understand what happened, so we can at least give David's family the answers they deserve.
"We also want to hear from anyone who witnessed the collision, or saw a pedal cyclist being pursued by someone, to call us. This happened very close to the BBC building so we believe there will be a lot of people who potentially saw what happened.
"We do know that David had a phone, we believe a white BlackBerry, and this has not yet been recovered. If you are that cyclist and took David's phone, do the right thing and hand yourself in: there is a close-knit family going through the most unimaginable grief who deserve to know what led to Saturday's tragedy."
Anyone with information is asked to call Bradford Park CID on 0161 856 3543 or 3540 or independent charity Crimestoppers anonymously on 0800 555 111.
