Cardinal Javier Lozano Barragan, head of the Pontifical Council for Health Care Ministry, said the document would focus, at least in part, on condom use by married couples when one spouse is infected.

He said the document would be made public soon, but refused to give details about the commission's conclusions.

Cardinal Lozano was responding to questions in the wake of an interview by Cardinal Carlo Maria Martini, retired archbishop of Milan, who said use of condoms can be the lesser evil in some situations.

Cardinal Lozano spoke in an interview April 23 with the Rome newspaper La Repubblica. He was asked specifically about use of condoms by married couples seeking to prevent transmission of AIDS.

"It's a very difficult and delicate theme that requires prudence," Cardinal Lozano said.

"My council is studying this attentively with scientists and theologians expressly charged with preparing a document on the subject, which will be made public soon," he said.

"It was Pope Benedict who asked us to make a study on this particular aspect of the use of condoms by those with AIDS and other infectious diseases," he said.

In recent years, even as Vatican officials have criticized anti-AIDS condom campaigns, several bishops, theologians and Vatican officials have said they could envision situations in which condom use to prevent AIDS would be the "lesser evil" that can be tolerated.

Cardinal Lozano, for example, said in 2005 that if a husband had AIDS, it was a woman's right to ask him to use a condom.

In the context of married love, the church teaches that contraceptive techniques, including condoms, are immoral because they close off the possibility of procreation.

Some theologians, including those who are consultors to the Congregation for the Doctrine of the Faith, have been among those suggesting that condom use by married couples may be acceptable when the intention is to prevent a deadly disease and not to prevent procreation.

Cardinal Martini told the Italian magazine L’Espresso that a spouse infected with HIV has an obligation to protect his or her partner.

At the same time, Cardinal Martini questioned whether religious leaders should promote anti-AIDS condom campaigns, because he said they risk promoting sexual irresponsibility.

That has been the primary argument of other church leaders, who have also said – as Pope Benedict did last June in a message to African bishops – that chastity and fidelity are the only fail-safe ways to prevent the spread of the disease.

In his interview with the weekly L’Espresso, Cardinal Martini also spoke at length about abortion. While calling for every effort to reduce the number of abortions, he said decriminalizing the practice has had the positive effect of reducing the number of clandestine abortions.

Decriminalizing abortion does not represent a "license to kill," he said. He said it means the state does not feel it necessary to intervene in every possible case; instead, he said, the state tries to eliminate the causes of abortions and prevents them from being carried out after a certain point in pregnancy.

Cardinal Martini also said that while one must do "whatever is possible and reasonable to defend and save every human life," there were complex and painful situations that require careful reflection and decisions on what is best for the person and what "concretely serves to protect or promote human life."

"It is important to recognize that the continuation of physical human life is not in itself the first and absolute principle. Above it stands human dignity, a dignity that in the Christian vision and that of many religions involves an openness to the eternal life that God promises to man," he said.

Physical human life should be respected and defended, he added, "but it is not the supreme and absolute value."

Cardinal Martini said he did not believe the principles of self-defense or "lesser evil" could be applied to cases of abortion, unless the mother's life was actually threatened by carrying the pregnancy to term.

Even when a mother cannot care for a child, he said, there are other ways in modern society for the child to be raised.

"But in any case I hold that respect is due to any person who, perhaps after much reflection and suffering, in these extreme cases follows their conscience, even if the person decides to do something that I cannot approve," he said.

The L’Espresso interview was conducted as a dialogue between Cardinal Martini and Italian bioethicist Ignazio Marino. In it, the cardinal touched on a number of other issues:

- The cardinal said he agreed with Marino that it appeared that individual human life began sometime after the joining of sperm and egg. In particular, Cardinal Martini said he agreed that a new individual did not seem to be present in a fertilized egg before the male and female nuclei had combined to form the new embryo's nuclei. That is an argument made by some scientists who are promoting new, more sophisticated forms of artificial insemination. Cardinal Martini said a more precise understanding of when individual human life begins could help overcome the church's opposition to every form of artificial insemination.

- The cardinal said the implantation of frozen embryos, so-called embryonic adoption, was preferable to simply letting the embryos perish – even when the mothers are single.

- On the question of allowing single people to adopt children, the cardinal said adoption by married couples was generally preferable, but that he would not want to exclude the possibility for singles. It is a question of making the best choice for the child, he said.