A lawsuit that had threatened to end the Obama administration's funding of embryonic stem cell research was dismissed Wednesday, allowing the United States to continue supporting a search for cures to deadly diseases over protests that the work uses destroyed human embryos.

Researchers hope one day to use embryonic stem cells in ways that cure spinal cord injuries, Parkinson's disease and other ailments. Paul Sancya/Associated Press

The lawsuit claimed research funded by the National Institutes of Health violated the 1996 Dickey-Wicker law that prohibits taxpayer financing for work that harms an embryo.The administration policy allows research on embryos that were culled long ago through private funding.

U.S. District Judge Royce Lamberth, chief of the federal court in Washington, last year said the lawsuit was likely to succeed and ordered a stop to the research while the case continued. Under swift protest from the Obama administration, however, the U.S. Circuit Court of Appeals in Washington quickly overturned Lamberth's injunction and said the case was likely to fail.

Lamberth said in his opinion Wednesday that he is bound by the higher court's analysis and ruled in favour of the administration's motion to dismiss the case.

"This court, following the D.C. Circuit's reasoning and conclusions, must find that defendants reasonably interpreted the Dickey-Wicker Amendment to permit funding for human embryonic stem cell research because such research is not 'research in which a human embryo or embryos are destroyed,"' Lamberth wrote.

Researchers hope one day to use embryonic stem cells in ways that cure spinal cord injuries, Parkinson's disease and other ailments.

Current research uses cells culled long ago

Opponents of the research object because the cells were obtained from destroyed human embryos. Although current research is using cells culled long ago, opponents also fear research success would spur new embryo destruction. Proponents say the research cells come mostly from extra embryos discarded anyway by fertility clinics.

President George W. Bush also permitted stem cell research, but limited the availability of federal money to embryonic stem cell lines that already existed and "where the life and death decision has already been made." Obama's order removed that limitation, allowing projects that involve stem cells from already-destroyed embryos or embryos to be destroyed in the future.

To qualify, parents who donate the original embryo must be told of other options, such as donating to another infertile woman.

The Obama administration's rules expanded the number of stem cell lines created with private money that federally funded scientists could research, up from the 21 that Bush had allowed to around 100 so far.

The lawsuit was filed in 2009 by two scientists who argued that Obama's expansion jeopardized their ability to win government funding for research using adult stem cells, ones that have matured to create specific types of tissues, because that would mean extra competition.