VATICAN CITY (AP, AFP) – The Vatican raised the possibility Sunday of using behind-the-scenes diplomacy to try to save the life of an Iranian widow sentenced to be stoned for adultery.

In its first public statement on the case, which has attracted worldwide attention, the Vatican decried stoning as a particularly brutal form of capital punishment.

Vatican spokesman the Rev. Federico Lombardi said the Catholic Church opposes the death penalty in general.

The Vatican said it was using “diplomatic channels” to intervene in the case, while Italy urged Iran for a “act of clemency.”

It is unclear what chances any Vatican bid would have to persuade the Muslim nation to spare the woman’s life. Brazil, which has friendly relations with Iran, was rebuffed when it offered her asylum.

Sakineh Mohammadi Ashtiani was convicted in 2006 of adultery. In July, Iranian authorities said they would not carry out the stoning sentence for the time being, but the mother of two could still face execution by hanging for adultery and other offenses.

Her son, Sajad, told the Italian news agency Adnkronos that he was appealing to Pope Benedict XVI and to Italy to work to stop the execution.

Lombardi told The Associated Press that no formal appeal had reached the Vatican. But he hinted that Vatican diplomacy might be employed to try to save Ashtiani.

Lombardi said in a statement that the Holy See “is following the case with attention and interest.”

“When the Holy See is asked, in an appropriate way, to intervene in humanitarian issues with the authorities of other countries, as it has happened many times in the past, it does so not in a public way, but through its own diplomatic channels,” Lombardi said in the statement.

In one of the late Pope John Paul II’s encyclicals in 1995, the Pontiff laid out the Catholic Church’s stance against capital punishment.

John Paul went to bat in several high-profile cases of death-row inmates in the United States. One of the first was the case of Paula Cooper, who was convicted of murdering her elderly Bible teacher when she was 15 but spared the electric chair by Indiana in 1989.

But that same year, a papal appeal for clemency to Cuba to spare a war hero and three other Cuban officers convicted of drug trafficking from the firing squad went unheeded.

Pope Benedict XVI did not make any mention of the case at the traditional Angelus blessing on Sunday.

Meanwhile, Italian Foreign Minister Franco Frattini on Sunday called on Tehran to grant clemency in the case, the ANSA news agency reported.

While reiterating his “full respect for Iranian sovereignty,” Frattini said “only an act of clemency could save the life of this person.”

He added that contacts had taken place with the Iranian embassy in Rome.

Frattini also recently said he had arranged to meet his Iranian counterpart Manouchehr Mottaki on the sidelines of the forthcoming UN General Assembly in New York.

Italy has strong economic ties, primarily energy interests, in Iran.

Tehran meanwhile has provisionally suspended the death sentence.

On Saturday, Mohammadi-Ashtiani’s son Sajjad said she had also been sentenced to 99 lashes for a photo of her without a headscarf published in a British newspaper.

A French petition has been signed by two former French presidents and Carla Bruni-Sarkozy, the wife of President Nicolas Sarkozy.

A hardline Iranian newspaper branded Bruni-Sarkozy a prostitute for signing the petition, with the French government describing the slur as “unacceptable”.

France has urged the European Union to threaten new sanctions against the Iranian regime over the stoning case, while EU foreign policy chief Catherine Ashton said talks were taking place with Tehran.