Dave Clark died following a fall while working on a stable block in Stanmer Park near Brighton last September.
He was was airlifted to St George’s Hospital in Tooting, London but died a month later.
A police spokeswoman told local paper The Argus: “A 67-year-old man from Brighton has been questioned and released on bail until 28 March and a 44-year-old man from Hove has been questioned and released on bail until 30 March.
“The incident is the subject of a joint investigation by Sussex Police and the Health and Safety Executive.”