Mr Anderson, 22, from the Short Strand area, suffered head injuries at Arthur Lane in the city centre in the early hours of Monday 6 February.
He was admitted to hospital later that day, but died nearly two weeks later.
Police want anyone who was in the Upper Arthur Street, Montgomery Street and Arthur Lane area on Monday 6 February at about 05:30 GMT to contact them.
The 26-year-old man was arrested on Tuesday morning.
Police investigating the murder of Belfast man Conan Anderson have arrested a 26-year-old man.