America’s main biological warfare lab has been ordered to stop all research into the deadliest viruses and pathogens over fears contaminated waste could leak out of the facility.

Fort Detrick, in Maryland, has been the epicentre of the US Army’s bioweapons research since the beginning of the Cold War.

But last month the Centers for Disease Control and Prevention (CDC) – the government’s public health body – stripped the base of its license to handle highly restricted “select agents”, which includes Ebola, smallpox and anthrax.