Arunasalam Arunothayan, 48, from Coventry, died in hospital on Thursday after being assaulted in Foleshill Road.
A 31-year-old man from the city has now been arrested on suspicion of murder.
Kirithas Sriskantharajah, 34, of Church Way, Bedworth, has appeared in court charged with murder and two other people have been arrested.
Mr Sriskantharajah appeared at Coventry Magistrates' Court on Monday, was remanded in custody and is due to appear at Warwick Crown Court sitting at Leamington on 11 March.
A 39-year-old man from Holbrooks and a 20-year-old woman have been arrested on suspicion of murder. The woman has been released on police bail.
Police investigating the death of a man who was assaulted at his home have arrested a fourth person.