The 46-year-old man was found at around 6.35am on Clumber Street on Wednesday, March 14 and later died in hospital.
Officers are still trying to establish his movements before he was found and believe there may be people who saw him walking around the area.
They are urging anyone who drove past Clumber Street or the surrounding area who has dash-cam footage, or anyone with any more information, to come forward.
A spokesman for Nottinghamshire Police said: “We appreciate that the CCTV images don’t clearly show faces, but we are hoping that someone may recognise the clothing.”
If you have any information call Nottinghamshire Police on 101, or Crimestoppers anonymously on 0800 555 111, quoting incident number 66 of March 14.
DID YOU SEE MAN BEFORE HE COLLAPSED IN MANSFIELD AND LATER DIED?: https://www.chad.co.uk/news/did-you-see-man-before-he-collapsed-in-mansfield-and-later-died-1-9071918MANSFIELD STREET CLOSED AFTER MAN FOUND COLLAPSED: https://www.chad.co.uk/news/update-mansfield-street-closed-after-man-found-collapsed-1-9062319