The man, who is in his 40s and from Cambridge, died after police were called to an incident at a premises in Ditton Lane at just after 6.30am. A post mortem is due to be carried out this morning at Peterborough City Hospital. The death is currently being treated as unexplained. The four men, three from Cambridge aged 40, 44 and 69, and a 50-year-old man from Fenstanton, were released on bail until February 11. A 45-year-old man arrested on suspicion of causing grievous bodily harm has been released with no further action taken.