Has the Institut Pasteur been shut down? Mais non! Stories in the press today suggesting that the venerable Parisian institution has been "closed" or ordered to halt its research have been greatly exaggerated, Pasteur Director-General Christian Bréchot tells ScienceInsider. "The institute is fully working," he says.

But Pasteur is struggling with a public relations fiasco after the discovery, made earlier this year, that it can't account for 2349 vials containing samples from the SARS outbreak in 2003. An independent panel has concluded that the risk for public health is zero, and Pasteur has suspended research in only one of its 18 biosafety level 3 facilities, Bréchot says. But the issue has led to three investigations and has raised questions in the media about the institute's safety procedures.

Today, the website Mediapart published fragments from a leaked letter written by two French Cabinet ministers who listed a series of apparent problems at the lab. "High likelihood of [sample] destruction not ordered by managers and without traceability, two-month delay in reporting the information to responsible authorities, lists of authorized persons not initially available, freezers not secured, absence of video surveillance, archives not available during weekend," wrote research and education minister Benoît Hamon and Marisol Touraine, minister of social affairs, in a letter that Mediapart says was addressed to two government inspectors charged with investigating the issue.

Pasteur staff discovered that the vials were missing during a regular inventory of dangerous pathogens in January, Bréchot says. The matter was reported to the National Agency for Medicines and Health Products Safety (ANSM), which inspected the lab between 8 and 12 April. On 12 April, Pasteur first announced the loss of the vials to the public in a short statement. Bréchot also reported the matter to the police, which is conducting its own investigation, and the two ministers have sent in their own inspection team. (The Institut Pasteur is a private foundation but the French government provides almost 30% of its annual budget.)

Bréchot says the vials contained patient material collected during the brief worldwide SARS outbreak, including nasal, trachea, and plasma samples. An extensive investigation among staffers and students to find out what happened to the samples was fruitless. Security measures would make it very difficult for someone to take them outside the lab, says Bréchot, who thinks the most likely explanation is that the samples were accidentally destroyed. "But we don't know how it happened," Bréchot says, "and that is clearly unacceptable."

Even if the specimens had left the lab, they would be harmless, Bréchot says. In the past, all attempts to isolate the SARS virus from the samples had failed; what's more, the vials had previously thawed for several days when the freezer in which they were stored broke down, reducing the chances of any virus surviving, he says. A panel of independent experts that examined the risks concluded that the "infectious potential" was "zero," according to the institute's statement.

Bréchot says the institute is now working with ANSM to completely review and improve the way it handles dangerous agents. "My job as president is to make sure this never happens again," he says.