A French scientist who is a member of a cult which believes that mankind was created by extra-terrestrials has claimed the group has produced the first-ever cloned human being.
Raelian cult member Dr Brigitte Boisselier says the baby girl was born by caesarean section and the birth "went very well".
It has not been possible to independently confirm the baby is in fact a clone because the effort by the Raelians to achieve the first human birth by cloning was carried out in secrecy.
A French geneticist, Axel Kahn, has told French radio that there is so far "absolutely no proof" that the claim was genuine and until such proof was provided the Raelian statement should be seen as "propaganda, pure and simple".
"Scientists would need to map the baby's genetic code and the genetic code of the person of whom it's said to be a clone and prove that the two are identical," he said.
"And then there is no technique until now that has worked with either apes or humans: are the Raeliens the first to have achieved this? There is no reason to believe that is the case today."
In her statement Dr Boisselier, a French chemist who is also president of the Clonaid human cloning society, declined to give further details of the birth, saying that a full press conference is scheduled in Florida.
"We are very happy. It's a triumph," Clonaid spokeswoman Nadine Gary said earlier.
If scientifically confirmed by independent sources, it would be the first human baby produced by the highly controversial technique - and announced publicly.
It would also mark the beginning of a new era in human reproduction - the first time a child was produced that was not the product of a genetic mix of mother and father, but the identical copy of one of its parents.
The predominant method around the world entails removing the nucleus, or core, from an egg and replacing it with DNA from a donor.
This DNA "reprograms" the egg, transferring into it the entire genetic code of the donor.
Clonaid, which is based in Las Vegas, Nevada, was founded in 1997 by the Raelians, who claim 55,000 followers worldwide.
The Raelians believe that life on Earth was established by extra-terrestrials who arrived in flying saucers 25,000 years ago, and that humans themselves were created by cloning.
The movement's founder, Rael - former French journalist Claude Vorilhon - lives in Quebec.
He describes himself as a prophet and claims that cloning will enable humanity to attain eternal life.
Apart from the ethical issues, scientists say the main technical problem is to ensure that all the genes in this transferred code work properly, performing the dazzlingly complex business which is the making of tissue and the repairing of it.
Wide-ranging tests in lab animals and the experience of cloned farm animals including Dolly the sheep, have found that, even though all the genes are there, many of them do not appear to switch on and off as they should.
Malfunctioning genes can cause an embryo to become malformed, prompting the body to expel it in a miscarriage.
Many biotechnologists are repelled by the ethical dilemma posed by human cloning as well as the risk to the first cloned babies, and many governments have raced to pass laws that ban reproductive cloning of humans.
Nevertheless, maverick scientists around the world claim to be engaged in a race to produce the first human cloning birth.