A man arrested this week suspected of involvement in the theft and leaking of a medical file on injured ex-Formula One champion Michael Schumacher was found hanged in his cell Wednesday, prosecutors said.

The man, whose identity was not disclosed, worked for a Swiss helicopter air rescue company, Rega, which organised the sportsman's transport from a French hospital to Switzerland in June, the Zurich prosecutor's office said in a statement.

The man, arrested Tuesday and interrogated by police, had denied any wrongdoing. He was being detained in a Zurich jail cell, the statement said.

He was found hanged when officers came to bring him breakfast before a scheduled hearing before a judge.

According to an initial investigation, no one else was involved in his hanging, the prosecutor's office said.

French prosecutors last month tracked down the IP address of the computer used in the theft of the medical records to Zurich-based Rega, which is the main operator of air ambulances in Switzerland.

The company denied any wrongdoing, and had, along with Schumacher's family, pressed charges against "unknown persons" for violating professional secrecy.

The records were stolen and offered for sale to a number of journalists for 50,000 euros ($68,000).

The Zurich prosecution said Wednesday that the man found hanged in his cell was believed to have acted alone in the case, but stressed he should be presumed innocent until proven guilty.

Schumacher spent more than five months in hospital in the French city of Grenoble after sustaining serious head injuries in a skiing accident at Meribel on December 29.

The former champion driver, long a resident of Switzerland, was brought by ambulance on June 16 from Grenoble to a cutting-edge clinic in the Swiss city of Lausanne.

The transfer was conducted with utmost secrecy.