The former US surgeon general has launched a blistering attack on the White House saying it deliberately quashed or downplayed several important health reports for political reasons.
Dr Richard Carmona, who held the post as the country's chief health educator from 2002 to 2006, told lawmakers that he was not authorized to discuss certain sensitive subjects in public.
They included embryonic stem-cell research, something US President George W. Bush vehemently opposes and has refused to fund, the controversial morning-after pill and sex education.
Senior administration officials also delayed the publication of a major study on passive smoking for several years and then tried to minimize its conclusions, Carmona said Tuesday according to a transcript of his testimony to a House committee.
The former surgeon general admitted that when he had taken up his post he had been "still quite politically naive" but he was "astounded" by the "partisanship and political manipulation" he witnessed.
He asked his predecessors for advice and was told "they had all been challenged and had to fight political battles in order to do their job.
"But each agreed that never had they seen Washington, DC so partisan or a new surgeon general so politically challenged and marginalized as during my tenure," he added.
"The problem with this approach is that in public health, as in a democracy, there is nothing worse than ignoring science, or marginalizing the voice of science for reasons driven by changing political winds."