The man, who was not named, worked as a manager at Swiss helicopter company Rega, which was involved in Schumacher's transfer from Grenoble hospital to University Hospital of Lausanne (CHUV) on June 16 after he emerged from a coma.
Seven-time F1 winner Schumacher, 45, suffered severe head injuries in a ski accident in the French Alps late last year.
The French daily "Le Dauphine Libere" reported in early July that leaked documents being offered to European media for some 60,000 Swiss francs ($67,200) appeared to have come from the IP address of a computer at a Zurich-based helicopter company.
Rega lodged a criminal complaint on July 8 for the suspected leak of Schumacher's medical files, but said at the time it had no proof that one of its employees was implicated.
An investigation by Zurich's cantonal prosecutor led to the arrest of a Rega employee on Tuesday in connection with violating patient privacy and medical secrecy.
The man, who was due to be questioned on Wednesday, denied the allegations. The cantonal prosecutor said it had found no indication that a third party was involved in the death of the man.
Rega CEO Ernst Kohler said in a statement on Wednesday that the helicopter company was "saddened" by the "tragic event."
Schumacher, who won a record 91 Grand Prix victories, left the sport last year after a disappointing three-year comeback with Mercedes following an earlier retirement from Ferrari at the end of 2006.
Schumacher's wife Corinna and teenage daughter and son live in the family home midway between Geneva and Lausanne.