The primary claim of Stanley Pons and Martin Fleischmann was that of excess heat, which they were expertly qualified to measure. They suspected that their chemistry experiment had yielded some form of nuclear reaction, an area of study, however, in which they were not highly skilled.

One of their sets of nuclear measurements was wrong, and critics jumped to the conclusion that this mistake was the rational explanation for the astounding claim of excess heat. Some critics alleged that it was not just a mistake but, of more sinister nature, intentional fraud.

A clear, concise and precise account of this history had been difficult to obtain directly from Fleischmann or Pons; they have been reluctant to discuss this matter.

Some accounts of this incident refer to a gamma-ray spectrum that was submitted to Nature by Fleischmann and Pons around the time of the Journal of Electroanalytical Chemistry April 10, 1989 publication, however this manuscript was rejected and never published by Nature.

Other citations, such as that of Marvin Hawkins in Nature (1989. 339(622,): p. 667) refer to a "somewhat strange approach to the collection of scientific data," stating that MIT researchers based their assessment on the television broadcast of a gamma spectrum, which Hawkins states was not a spectrum made in his, Fleischmann and Pons' laboratory.

It appears that an important peak in the gamma ray spectrum changed, without clear explanation, between 2.2 MeV to 2.5 MeV - possibly more than once. It is unclear as to whether the value for the peak changed before or after the April 10, 1989 JEAC paper, or perhaps both.

News stories, such as a letter published on April 9, 1991 by Robert Adair in The New York Times, indicated that the change was the result of a recalibration. Adair served on an a Utah oversight commitee for cold fusion research.

"Their recalibration of the gamma ray energy data was neither dishonest nor unusual. The problem was not the calibration but that the whole measurement was, as Dr. Fleischmann says, 'rubbish.' And their failure to describe that calibration in their brief publication was not extraordinary."

The accusations of fraud were first made by Ronald R. Parker, the director of the MIT plasma fusion center, on April 28, 1989, in an interview with Nick Tate of the Boston Herald.

Another senior scientist at the MIT plasma fusion center, Richard Petrasso, was quoted two years later in the March 17, 1991, issue of The New York Times that MIT was mistaken to allege fraud. “I was convinced for a while it was absolute fraud," he said. "Now I’ve softened. They probably believed in what they were doing."

Fleischmann and Pons individually had visited the staff at Los Alamos National Laboratory on two occasions in the first few years after the discovery. Edmund Storms, who performed research on materials used in nuclear power and propulsion reactors there, now retired after 34 years of service, explains this part of cold fusion history from his perspective.