He said he felt alone, but never did I imagine he would do something like this

Friend and rival Umberto Pelizzari

Police said Mayol had hanged himself on Saturday. His body was found on Sunday by a worried neighbour.

His Italian friend and rival Umberto Pelizzari said the 74-year-old had been depressed in recent months.

"He said he felt alone, but never did I imagine he would do something like this," Mr Pelizzari said. "I considered him my master."

Diving daredevil

In 1976 Mayol became the first man to reach 100 metres (330 ft), a record he followed up in 1983 with a free dive to 105 metres (346 ft) at the age of 56.

Mr Pelizzari later beat this record with a free dive of 131 metres (432 ft).

Mayol was the first man to dive to 100 metres without oxygen

Mayol's life formed the basis of Luc Besson's 1988 film The Big Blue, which he co-wrote, and which proved very successful at the European box office.

French President Jacques Chirac hailed Mayol, who was born in 1927 in Shanghai, as a "visionary, who for the 'Big Blue generation' will remain as a symbol of the quest for the absolute."

Police said they found a letter at his home in which Mayol asked to be cremated.

The ceremony is due to be held in the coming days in the Italian town of Livorno.