What magic is there in embryonic stem cells to make some scientists so economical with the truth and some science journals so credulous? Only a few months after the disgraceful Korean stem cell scandal, another scientist has again announced a breakthrough, and has again been denounced as a liar.

Last week a Massachusetts company declared that it had mastered a technique for creating "ethical" embryonic stem cells which could break the logjam in America's stem cell politics. The world's leading science journal, Nature, rushed the news into its on-line express edition. Since stem cells could become the key medical platform for the 21st century, finding a way to harvest the most versatile variety without destroying human embryos would have been a major coup. And this is the way Advanced Cell Technology described its work in a press release.

"We have demonstrated, for the first time, that human embryonic stem cells can be generated without interfering with the embryo's potential for life," said lead author Robert Lanza.

CEO William Caldwell delivered the same message: "we do not destroy the embryo. That's the whole purpose of what we perceive to be a major scientific breakthrough." Ronald Green, a bioethicist at Dartmouth who heads ACT's Ethics Advisory Board, gave it his blessing. "This technique overcomes this [ethical] hurdle and has the potential to play a critical role in the advancement of regenerative medicine."

But their claim was false. None of the embryos described in the paper had survived. Talk of breaking the impasse was a con.

What Lanza's team had done was to biopsy an eight-cell human embryo and gently remove a single cell -- a standard technique nowadays in IVF. With this cell Lanza created a stem cell line while the embryo continued to develop normally. At least that was what he intended. In fact, although 16 embryos were dismembered into 91 separate cells, Lanza produced only two stem cell lines.

"It was a very disruptive, very wasteful, very inefficient procedure, and it left all the old embryos dead, just like the old method did," said Richard Doerflinger, the pro-life spokesman for US Catholic Bishops, who blew the whistle on ACT's claims. In a rare moment of consensus on the controversial issue of embryonic stem cells, even supporters of therapeutic cloning dismissed Lanza's work. "A pitiful attempt to look morally acceptable, rather than do valuable science," sneered Glenn McGee, editor of the American Journal of Bioethics. Even the Australian IVF industry dismissed ACT's claims as "absurd" and "over-sold".

The most astonishing feature of this shabby episode is that the publication as prestigious as Nature colluded in it. It rushed Lanza's article into print, accepted his line about an ethical breakthrough, and even posted an on-line image of a mature, healthy embryo which had survived a biopsy. Nature should have known about the dubious ethics of harvesting embryonic stem cells from biopsies. Only last year these were thoroughly canvassed in a major white paper by the President's Council for Bioethics.

Furthermore, Advanced Cell Technology has a track record as a publicity hound. A listed company which is perpetually in the red, it burst onto the front page back in 2001 claiming that it had cloned a human embryo and initiated a stem cell line. Nothing came of that extraordinary wave of publicity, but it no doubt put ACT scientists in the rolodexes of journalists across the world.

This episode should ring warning bells for everyone interested in the controversy over embryonic stem cells. ACT recently shifted its headquarters from Massachusetts to California in the hope of obtaining some of the US$3 billion in state money that will soon become available for work on embryonic stem cells and therapeutic cloning. Disbursement has been held up by legal action. But when the funds flow, the feeding frenzy will begin. "We have to have very discerning review boards so it doesn't become a boondoggle for companies that haven't succeeded," Dr. Irving Weissman, a prominent stem cell researcher at Stanford University, has commented.

After Nature's undiscerning treatment of Lanza's stem cell work, however, it seems more likely that destructive research on embryos will slip through with a wink and a nod.

This is tragic, since it may not be necessary to clone or destroy embryos to get those precious stem cells. In a highly significant development earlier this month, Japanese scientists reported in Cell, another major journal, that they had reprogrammed an adult mouse cell and converted it into something closely resembling an embryonic stem cell.

Researchers from a stem cell group at Harvard University grudgingly acknowledged that it was a "significant step" -- "unencumbered by neither the logistical constraints nor the societal concerns presented by somatic cell nuclear transfer [i.e., cloning]." If this success can be replicated with human cells, it might indeed transform America's stem cell politics.

Michael Cook is editor of BioEdge, a weekly bioethics newsletter. Email: mcook@australasianbioethics.org.