Investigations into charges of scientific misconduct are unpleasant for all concerned. Emotions run high and careers are jeopardized. As a consequence, it is crucial that all those involved, both directly and indirectly, behave with dignity and restraint.

But events around such an investigation in Germany have taken a troubling and damaging turn from such good practice in the past few months. An unknown agitator using the presumed pseudonym Marco Berns is engaged in an e-mail and Internet offensive against two biomedical researchers whom he accuses of scientific fraud.

Berns's libellous messages are targeted at dermatologist Ralf Paus and immunologist Silvia Bulfone-Paus, a married couple who both hold joint positions at the University of Manchester, UK, and the University of Lübeck, Germany.

The trial-by-Internet is disturbing a formal investigation, organized by the Research Center Borstel in Germany and begun in July, into some of the pair's publications.

Berns began sending e-mails to those involved in the inquiry shortly after it started, and has since widened his reach to researchers, politicians and journalists. He provides links to an untraceable website hosted in Panama, which contains more material.

Those involved in the investigation are rightly appalled by the destabilization that these public accusations could cause. Claims of scientific misconduct must be assessed in confidence to protect both accused and whistle-blower from rumours that could prejudice the inquiry.

But under the shadow of anonymity, it seems that little can be done to stop Berns. Upset and uncertainty will remain until the investigation is complete. Everyone involved must be presumed innocent until then, and the inquiry should report as quickly as possible without sacrificing fairness, impartiality and normal procedure. That is the best that can be done in this unfortunate affair.