A Spanish village has declared a day of mourning following the death of a retired farmer billed as "the world's oldest man", who passed away just over a month after turning 113.

Francisco Nunez Olivera, who was ten years old when World War I broke out, died yesterday in the village of Bienvenida in southwestern Spain where he had lived throughout his life, village mayor Antonio Carmona said.

"It's a very cold day and most of all a very sad day," Mayor Carmona said.

Born on 13 December, 1904, relatives credited Nunez Olivera's long life to a diet based on vegetables he grew on his own land and a daily glass of red wine.

Every morning for breakfast, he would have sponge cake made with olive oil and a glass of milk. Until the age of 107, he went out for daily walks by himself, according to Spanish media reports published when he celebrated his last birthday.

While the Spanish media described Nunez Olivera as the world's oldest man, his name did not appear on a list kept by the Gerontology Research Group, which validates the ages of the world's longest-living people.

The US-based group lists Japan's Masazou Nonaka, born on 25 July, 1905 making him 112, as the world's oldest man but Mayor Carmona said there were documents to prove the Spaniard was in fact older.

It also lists a Japanese woman, aged 117, as the world's oldest person.

Mediterranean diet benefits?

"We were in the process of applying for him to enter into the Guinness Book of World Records. It meant a lot to his neighbours to be represented by the oldest man in the world," Mayor Carmona said.

Proving Nunez Olivera's exact age has been complicated by the fact that most of Bienvenida's public archives were destroyed during Spain's 1936-39 civil war, according to newspaper El Mundo.

Nunez Olivera, known in the village as Marchena due to his likeness to a Spanish flamenco singer who used that stage name, had been a widower since 1988.

He fought in the Rif War in the first half of the 1920s between Spain and the Berber tribes of the Rif mountains in Morocco and survived General Francisco Franco's 1936-75 dictatorship.

This afternoon, he was to be buried in Bienvenida.

He was one of 32 people over the age of 90 among the roughly 2,200 inhabitants of the village, according to El Mundo.

Spain has one of the highest life expectancies in the world, which doctors often attribute to the country's Mediterranean diet.