Purdue University announced on Tuesday that it had finished its investigation of Rusi P. Taleyarkhan, a professor of nuclear engineering. Over the past four years, Mr. Taleyarkhan has made headlines by reporting that focused sound waves can generate nuclear fusion, raising hopes that the relatively low-cost method could succeed where giant reactors have failed in producing a viable source of energy from fusion. But no independent team has corroborated his experiments, and researchers both at Purdue and elsewhere have questioned Mr. Taleyarkhan’s results (The Chronicle, March 9). The university said it would not release the findings of the investigation, which began in March.

“The committee has submitted a report, and I will take appropriate action after studying the recommendations,” said Charles O. Rutledge, vice president for research. “Any further action in this matter will be conducted as an internal matter under appropriate university procedures.”