Academic researchers working with dangerous pathogens should not be subjected to the same stringent background checks currently required for scientists working in chemical and nuclear weapons programmes, a panel of US government advisers recommended last week.

The National Science Advisory Board for Biosecurity report, released on 29 April, examined how to reduce "insider threats" posed by bioscientists with malicious intent. It noted that security regulations governing bioscientists were bolstered after the US anthrax attacks of 2001, and said they should continue to be strengthened.

But piling on "onerous" requirements, it said, could cause the best scientists to shun important work with pathogens and could isolate those that remain in the field.

A working group, established by former president George W. Bush in January, is reviewing US lab biosecurity and is expected to report in July.