Where has all the data gone? Three classified flash drives showed up in a trailer.Getty

Classified data from Los Alamos National Laboratory, the first US nuclear-weapons lab, turned up last week at the home of a drug dealer in New Mexico.

The Federal Bureau of Investigation is investigating the breach, the latest in a string of security-related embarrassments for the lab. In 2000, two hard drives containing classified data disappeared briefly. And in 2004, the lab was shut down for months after two disks were reported missing; it later turned out that the disks never existed (see Nature 433 , 447; 2005).

Local police have now found three flash drives containing classified material during a search of a trailer home occupied by a known methamphetamine dealer. A former subcontractor at the lab was also living there. At least one of the drives was traded for methamphetamine, the dealer told the local newspaper from his jail cell.

Los Alamos director Michael Anastasio said the lab is trying to find out what went wrong. "This is a serious matter, and we are taking immediate steps to address it," he says.

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