New Jersey’s Acting Governor Richard Codey on Tuesday urged President George W. Bush to lift restrictions on federal funding for stem-cell research given a recent report that says that available human embryonic stem cells are contaminated.

Codey, in a letter to the president, challenged Bush’s executive order restricting federal funding for stem cell research to only those lines - or batches of cells - that existed when the order was signed in 2001. Researchers hope the cells could lead to cures for Alzheimer’s, Parkinson’s and spinal cord injuries.

Citing research released on Sunday, Codey said the available stem cells were contaminated with an animal molecule and may not be suitable to treat people.

The research by the University of California at San Diego and Salk Institute for Biological Studies at La Jolla, said the stem cells were contaminated with a foreign molecule from mice.

“Why should our national policy force our best scientists to spend years researching a way to clean up contaminated stem cells when other stem cells exist that can advance scientific knowledge today?” wrote Codey, a Democrat. Codey took over last November when former Gov. James McGreevey stepped down after confessing to a homosexual affair with a former aide.

Codey said two weeks ago that New Jersey, home to major pharmaceutical firms, will spend $380 million to build a stem-cell research institute, making it America’s second-biggest public backer of the research after California.

Bush, whose re-election was aided by anti-abortion Christians, opposes the use of stem cells from human embryos.

White House spokesman Jim Morrell said federal government scientists have always known that the authorized stem cells contained “animal traits” and are convinced the 60 available stem cell lines hold the possibility of scientific advances.