Vatican City -  The Vatican hit back Friday at allegations made by dissident Catholic groups calling on Pope Benedict XVI to reverse what they said was the Catholic Church's "catastrophic" stance on contraception.

The groups, from countries including Britain, Brazil, Canada, France and the United States, wrote an open letter to the pontiff published in Italian daily Corriere della Sera on Friday.

The letter, the publication of which was paid for by the groups, appeared on the 40th anniversary of the late Pope Paul VI's encyclical Humanae vitae (On the Regulation of Birth), which declared it a sin to use such methods as the contraceptive pill and the condom.

In the letter, the signatories allege that the effects of the Vatican's condemnation of artificial birth control had been "catastrophic," especially in poor countries of the world.

The letter criticises a stance it says "puts the lives of women in danger and exposes millions of people to the risk of contracting the AIDS virus."

But papal spokesman, Father Federico Lombardi, dismissed the letter as "paid-for propaganda in favour of the use of contraceptives" and said the groups, who were "well known" to the Vatican for their views that ran contrary to Church teachings, represented "nothing new."

"In addition the harshest accusation, that the Catholic position causes the spread of AIDS, and thus pain and death while obstructing enlightened health policies, is manifestly unfounded," Lombardi told Vatican Radio.

"The spread of AIDS is completely independent from the religious faith of populations and of the influence of the clergy, while polices against AIDS based on the distribution of condoms have largely failed," Lombardi said.

Paul VI's 1968 encyclical, in condemning the use of artificial birth-control methods, said sexual intercourse cannot be separated from the purposes of procreation within marriage.

The position was upheld by the late Pope John Paul II and his successor, Benedict. (dpa)