The man, believed to have been a council employee, was arrested at his Birmingham home on Thursday in connection with the death of an 82-year- old man at the Summer Hill hostel for single homeless men in Ladywood, Birmingham, in 1988.
He was detained at Birmingham's Rose Road police station, Harborne, and was being questioned by detectives yesterday.
The offences are alleged to have taken place over a 14-year period prior to April 1993 when the hostel - previously managed by the Labour-led city council - was taken over by the Focus Housing Association.
A West Midlands police spokeswoman said: "One murder and a number of other suspicious deaths are being investigated - but whether they are murders is anyone's guess."
Detective Superintendent Bob Minshull of West Midlands Police said: "I can confirm that we are conducting an investigation into allegations of physical abuse of residents at Summer Hill hostel in Birmingham. The allegations were referred to police by social services following their own internal investigation."
Police have not yet named the victim and would not reveal what area of Birmingham the arrested man comes from.