The scientists included in the OPERA experiment, conducted at the Gran Sasso laboratory near Rome, said some of the neutrinos beamed to them from the CERN research center in Switzerland traveled faster than the speed of light.
Now, a study called ICARUS at Gran Sasso indicates that the energy levels of the arriving neutrinos were too high. If the neutrinos were indeed traveling faster than light, they would have lost most of their energy, claims the ICARUS team.
"The difference between the speed of neutrinos and the speed of light cannot be as large as that seen by OPERA, and is certainly smaller than that by three orders of magnitude, and compatible with zero," said CERN physicist Tomasso Dorigo, commenting on ICARUS' results.
Full results of the ICARUS study can be found here.
Another recent experiment by CERN confirmed the findings of the original experiment in September, but it may have been prone to the same errors - if any existed - as the original experiment.
Independent experiments are being prepared in Italy, U.S. and Japan to try to replicate OPERA's results.