A BOOK offering Asian mysticism and spirituality as the keys to life has become this summer’s bestseller in Roman Catholic Italy, provoking growing alarm at the Vatican.

La Fine è Il Mio Inizio (The End is My Beginning), by Tiziano Terzani, a former war correspondent, has sold 400,000 copies and gone into four editions since it was published posthumously in March — an astonishing figure in a country where bestseller normally means 100,000 copies.

Terzani, an expert on China and Japan who covered wars from Vietnam to Afghanistan before adopting a long white beard and robe and living in an Indian ashram, argues that people have an “innate moral sense” and do not need institutionalised religion to teach them right and wrong.

The former Communist, whose mother was a devout Catholic, outlines a philosophy of Indian spirituality, communion with nature and “the harmony of opposites” that he said helped him in his fight against cancer. He deplores the impact of Western materialism on Asia and describes how his growing pacifism made him a bitter opponent of war, and especially of the Bush Administration’s War on Terror.

This week Avvenire, Italy’s leading Catholic daily, accused Terzani of “leading people astray”. He had “completely lost sight of the incarnate and historical dimension of religious experience”. Alessandro Gnocchi, a Catholic author and television presenter, accused Terzani in the conservative newspaper Libero of peddling “a confused mixture of Oriental philosophy, Marxism and Christianity” that muddled “St Francis with Zen Buddhism”.

Vatican sources said that this was anathema to Pope Benedict XVI, who, as Cardinal Joseph Ratzinger and head of the Congregation for the Doctrine of the Faith, warned of the dangers of trying to reconcile Oriental and New Age spirituality with Catholicism.

Terzani’s website has been indundated with admiring e-mails. The book was “a beautiful journey towards the authentic meaning of life,” reads one from Carlo. “I was knocked out,” writes Luisa.

“Terzani has become the lay Pope,” said Panorama magazine. La Stampa said that a “cult” had grown up around the former journalist, making him “an icon, a secular saint”.

Massimo De Martino, the founder of the Terzani Fan Club, said that Terzani had never been a “guru” but had simply “shared his life experiences”. Terzani’s son Folco said: “I don’t want to get involved in this polemic — but my father a saint? You might as well ask if he was a footballer.”

Giuliano Amato, the Interior Minister, who was a lifelong friend, said: “To transform Tiziano into a saint would be to do a disservice both to him and his legacy.”

Terzani, born in Florence in 1938, wrote for Der Spiegel, Corriere della Sera and La Repubblica, with postings in Tokyo, Singapore, Hong Kong, Bangkok, Delhi, and Beijing, from where he was expelled for “counter-revolutionary activities”.

His first book, Pelle di Leopardo (Leopard Skin), which described the Vietnam War and its aftermath, begins: “War is sad. Even sadder is that you get used to it.” Other books include Un Altro Giro di Giostra (One More Ride on the Merry-Go-Round), about his search for a cancer cure. In it, he says: “In time the goal of my journey became the cure not for my cancer, but for the sickness which affects all of us: mortality.” He died in 2004, aged 65.