The US Supreme Court declined Monday to enter the emotionally-charged debate over stem cell research, refusing to hear an appeal centered on the issue of federal government funding.
The top US court did not give a reason for its decision, which ends the long judicial saga over President Barack Obama's 2009 executive order lifting restrictions on financing imposed by his predecessor George W. Bush.
The appeal had come from two researchers working with adult cells rather than embryonic stem cells.
They had asked the Supreme Court to halt financing for stem cell research on the grounds that federal law banned the creation and destruction of embryos for scientific study.
Stem cell research is said to be promising for finding new treatments for a variety of diseases.
A federal judge banned the financing in 2010, but an appeals court in Washington reversed the ruling in 2012. The court said the federal ban does not apply to previously existing embryos that resulted from in vitro fertilization procedures.
Government financing through the National Institutes of Health was authorized for cells from frozen embryos that were left over from fertility treatments.
The NIH, which allowed researchers to use stem cells derived from donated frozen embryos no longer needed for fertility treatments, hailed the ruling.
"This decision allows the ruling to stand, and enables NIH to continue conducting and funding stem cell research, following the strict ethical guidelines put in place in 2009," NIH Director Francis Collins said in a statement.
"Patients and their families who look forward to new therapies to replace cells lost by disease or injury, or who may benefit from new drugs identified by screening using stem cells, should be reassured that NIH will continue supporting this promising research."