US authorities have asked the authors of two controversial bird flu studies to redact key details after a government advisory panel suggested the data could be used by terrorists.
The papers show how a bird flu variant can pass easily between ferrets.
Editors at the journals Science and Nature say they will not agree to the redactions until they are assured the data will be accessible to researchers.
A spokesman for US health authorities said such a system was being prepared.
At least one set of scientists have already rewritten their paper in light of the recommendation, Science reports.
Albert Osterhaus told Science his team "completely disagreed" with the recommendation of the panel, the National Science Advisory Board for Biosecurity (NSABB).
But Mr Osterhaus, who believes the information should be made widely available, said an editorial explaining his team's "genuflection" to the panel is a condition of the paper's publication in Science.
A second research team at the University of Wisconsin, Madison is also reluctantly submitting a revised paper to Nature, a university spokesman confirmed to Science.
'Bona fide need'
While bird flu is deadly, its reach has been limited because it is not transmissible between humans.
However, the flu virus was altered in the new studies to be passed easily between ferrets.
Those mutations mean the flu would have "greater potential" to be contagious among humans, the NSABB said in a statement on Tuesday.
The lab-created version, the board warned, represented an "extremely serious global public health threat".
The NSABB recommended that the "general conclusions" be published but that final manuscripts not include details that "could enable replication of the experiments by those who would seek to do harm".
Editors at Nature and Science said they wanted a clearer plan from the US government about how the potentially redacted data could be used by "all those responsible scientists who request it".
"Many scientists within the influenza community have a bona fide need to know the details of this research in order to protect the public, especially if they currently are working with related strains of the virus," Science editor-in-chief Bruce Alberts said.
Mr Alberts said the magazine's response would be "heavily dependent upon the further steps taken by the US government to set forth a written, transparent plan" to ensure the information can be used by scientists who request it.
"It is essential for public health that the full details of any scientific analysis of flu viruses be available to researchers," Dr Philip Campbell, editor of Nature said in a statement.
The recommendation is unprecedented for the board, which was created in the wake of the 2001 anthrax attacks.
Speaking to the BBC, Anthony Fauci of the US National Institutes of Health (NIH) said a system to allow those with proper credentials to access the full research was now being put together.
It was expected to be ready in time for the publication dates during January, he said, but it was prudent to restrict key information to those directly involved in public health programmes.
"The critical question is whether there is a compelling public health reason to gain access to the knowledge," Mr Fauci said.
The Department of Health and Human Services said it agreed with the recommendation.
The research was partly funded by the NIH, the parent body of the NSABB, as part of "pandemic preparedness", Mr Fauci confirmed, adding that it was entirely proper that the NIH fund such research.
But he conceded that there was little the NSABB could do to stop the publication of the full papers if the editors of Science and of Nature decided to take that path.
"The journals want to publish but understand the concerns of the NSABB," Mr Fauci said.
NSABB is made up of scientists and public health experts, 23 from outside the government, and 18 from within. It cannot stop publication but makes recommendations to researchers.