At first sight, it looked like the biggest misconduct scandal for years: scientists at the world's largest research campus riding the gravy train of lucrative private consulting deals that have distorted research and possibly even led to the deaths of patients in clinical trials. At least, that is how an extensive article in the Los Angeles Times on 7 December portrayed the situation at the US National Institutes of Health (NIH).

In response to the coverage, a congressional committee has demanded records of consulting arrangements at the NIH going back four years. Hearings seem likely. And NIH director Elias Zerhouni has promised a thorough review of consulting practices and ethics rules.

Although such responses are appropriate, the magnitude of the offences seems unlikely to be as worrying as the article implied — which is probably why other media have not pounced on the story. What appears at first to be damning evidence of industry distortion of public medical research is actually rather inconclusive. The article details the consulting deals of a number of high-ranking NIH officials and describes how each posed an alleged conflict of interest. But it is also possible that each official was behaving within ethical bounds.

In one example, Stephen Katz, director of the National Institute of Arthritis and Musculoskeletal and Skin Diseases, was reportedly reluctant to halt a trial of an anti-inflammatory drug in the wake of a patient's death, while at the same time serving as a paid consultant to the maker of the drug. But Katz says he did not know that the drug was made by his client, because it was provided by a differently named US affiliate. Furthermore, as with all the other consulting deals mentioned in the article, Katz's was subject to ethical review and approval.

Permitting employees to engage in private consulting is essential to the vitality of the NIH. By the mid-1990s, the agency was losing talent to industry and academia, where higher pay and private consulting are common. When Harold Varmus took the helm in 1993, he was charged with revitalizing research. By allowing researchers to increase their consulting income, he helped to turn the tide.

The NIH's policies on such matters are open to public scrutiny (see http://ethics.od.nih.gov), but the practice is not. Private consulting, which in the NIH must be done in “personal time”, can open the way for conflicts of interest. Even assuming that proper safeguards are in place, one disturbing fact remains. Of the 2,259 current consulting deals made by NIH employees in the upper salary brackets, only 127 are subject to full public disclosure — a statistic that even Varmus says he finds disconcerting. The rest fall through an administrative loophole that permits many top-level researchers to file minimal details of their outside agreements, and then for internal use only.

As the pending congressional review demonstrates, the appearance of impropriety can be as damaging as impropriety itself. The only way forward is transparency. Public officials throughout government engage in private consulting, but that consulting must be open to public scrutiny. The public should not be asked to take the NIH's word that its staff are behaving well in such sensitive areas of responsibility. They should be able to see for themselves.