The Vatican has rejected a proposed ambassador from Bulgaria, because the candidate wrote a novel that featured the themes of homosexuality and prostitution.

Kiril Marichkov’s highly successful novel, "Clandestination," offended Vatican officials, placing his nomination to the Holy See in jeopardy.

The 39-year-old attorney, who speaks five languages and is married to an Italian woman, is also the grandson of the first Bulgarian ambassador appointed to the Vatican after the fall of communism.

Despite his sterling credentials, the Vatican will not approve his appointment.

His book is about illegal immigrants who escape Eastern Europe for Rome after the fall of the Berlin Wall. The principle character, a man named Ivan, is forced by poverty to sell himself to men for sex on the streets.

Archbishop Janusz Bolonek, Pope Benedict's representative in Bulgaria, reportedly brought the book’s contents to Vatican officials’ attention.

"Before someone becomes ambassador, there has to be agreement," said Father Federico Lombardi, the Vatican's chief spokesman.

"He has to be a good bridge between the two countries and has to be welcome."

The Daily Telegraph reported, however, that the former Bulgarian ambassador to the Vatican, Nikola Kaloudov, as well as the government in Sofia, are not willing to name a replacement for Marichkov.

Vatican officials are likely sensitive to the gay issue since so many Catholic priests around the world have been accused of homosexuality and pederasty. Moreover, according to the Independent newspaper, two years ago it was revealed that Pope Benedict's ceremonial ushers, and a member of the Vatican choir, were mixed up in a gay prostitution ring.

Bulgaria has had a troubled relationship with the Vatican for decades.

Following the attempted assassination of former Pope John Paul II in 1981 by a Turkish gunman named Mehmet Ali Agca, investigators in Europe suspected he had links and supporters in Bulgaria, possibly with the country’s spy agency or secret police.

Agca’s alleged Bulgarian links were widely believed.

However, in April 2011, a book called "Kill the Pope: The Truth about the Assassination Attempt on Pope John Paul II" by Italian journalist Marco Insaldo and Turkish journalist Yasemin Taskin found no evidence that Bulgaria had anything to do with the pope’s murder attempt.

They claimed that the CIA fabricated a Bulgarian conspiracy in order to discredit communism.

”The Bulgarian connection is the creation of the CIA," Insaldo said at the time.

Indeed, Agca belonged to the fiercely anti-communist Turkish nationalist group, the Grey Wolves. He apparently visited Sofia a number of times to forge links between his organization and Bulgarian mafia figures.

"Alexander Haig, then [U.S.] secretary of state, had asked the CIA to find anything that could be used against the communists," said Insaldo.

"The CIA knew the Grey Wolves had connections with Bulgaria through organized crime and that Agca had visited, so when he tried to kill the pope, they were very smart and exploited the connection."