The 36-year-old died after a late-night raid at a Gorakhpur hotel last month.
All six cops accused in the death of Kanpur businessman Manish Gupta have been arrested, the UP Police said, with the final arrest on Saturday. The death of the businessman had turned into a huge political controversy with many accusing the Yogi Adityanath government of inaction.
The 36-year-old died after a late-night raid at a Gorakhpur hotel last month where he was meeting his friends. His family had alleged that six policemen - led by a senior inspector - barged into their hotel room, and assaulted Mr Gupta. The cops also allegedly delayed taking him to the hospital.
The autopsy report showed he suffered multiple injuries, including a swelling in the middle of his head, a cut above the elbow joint and injuries to the upper lip.
Six cops were suspended immediately as the UP government faced searing criticism from the opposition leaders. The arrest of the six accused, which began on October 10, concluded on Saturday.
The family was initially dissuaded from pursuing the case, a widely shared video had earlier appeared to show.
The video apparently filmed by a family member of the killed businessman during a meeting with Gorakhpur district magistrate Vijay Kiran Anand and police chief Vipin Tada.
The clip appears to show the district magistrate telling the family that "a court case will take years". "I am requesting you like an elder brother. After a court case, you will not believe, it takes years in court," Mr Anand purportedly says in the video.
The video then appears to show police chief Tada interjecting, and saying "they (cops) did not have any previous enmity. They went in uniform and that is why I am listening to you since morning. You asked for them to be suspended and I did that. They will not be reinstated till they get a clean chit."