Purdue University is investigating complaints about a scientist who claimed to have achieved cold fusion using sound waves to make bubbles in a test tube, the university has said.
Nuclear engineer Rusi Taleyarkhan's work has been controversial since he published a study in 2002 claiming to have achieved the Holy Grail of energy production - nuclear fusion at room temperature.
Nuclear fusion is the process that powers the sun.
If scientists can duplicate the results and harness the technology, tabletop fusion has the potential to provide an almost limitless source of cheap energy.
Many labs are working frantically to try to do so, but their efforts are difficult to substantiate and especially susceptible to being labelled as fraud.
Taleyarkhan, whose study was published while he was at the US Department of Energy's Oak Ridge National Laboratory in Tennessee, now works at Purdue University in Indiana and has also been trying to replicate his earlier findings.
He claimed to have done so in 2004.
Sally Mason, Purdue provost, said her office was checking complaints from some of Taleyarkhan's co-workers. "Purdue last week initiated a review of this research and these allegations," Mason said in a statement on Wednesday.
"The research claims involved are very significant and the concerns expressed are extremely serious. Purdue will explore all aspects of the situation thoroughly and announce the results at the appropriate time," she added.
"To ensure objectivity, the review is being conducted by Purdue's Office of the Vice President for Research, which is separate from the College of Engineering."
N-fusion at room temperature is
the goal of energy researchers
The journal Nature reported on Wednesday that it had interviewed several of Taleyarkhan's colleagues who suspect something is amiss.
"Faculty members Lefteri Tsoukalas and Tatjana Jevremovic, along with several others who do not wish to be named, say that since Taleyarkhan began working at Purdue, he has removed the equipment with which they were trying to replicate his work, claimed as 'positive' experimental runs for which they never saw the raw data, and opposed the publication of their own negative results," Nature said in a statement.
"In addition, Brian Naranjo at the University of California, Los Angeles, is submitting to Physical Review Letters an analysis of Taleyarkhan's recently published data that strongly suggests he has detected not fusion, but a standard lab source of radioactivity."
Naranjo's lab reported in April 2005 that it had achieved cold fusion by heating a lithium crystal soaked in deuterium gas.
Engineers and physicists have been cautious about Taleyarkhan's technique but say in theory it could work.
"Purdue will explore all aspects of the situation thoroughly and announce the results at the appropriate time"
Purdue University Provost
In his original report, published in the journal Science in 2002, Talayarkhan and colleagues said they created nuclear fusion in a beaker of chemically altered acetone by bombarding it with neutrons and then sound waves to make bubbles.
When the bubbles burst, the researchers said they detected fusion energy. The 2004 experiment used uranyl nitrate, a salt of natural uranium.
Experts have been especially sceptical about cold fusion claims since Britons Martin Fleischmann and Stanley Pons of Southampton University held a news conference in 1989 to claim they had achieved it.
Announcing a major scientific advance in a news conference rather than submitting experiments to expert peer review and scrutiny is considered poor form by scientists - and Fleischmann and Pons were further ridiculed when no one could duplicate their efforts.