Four more Los Alamos National Laboratory (search) workers have been put on paid leave in a widening probe into two missing computer disks containing classified information, officials said Wednesday.

Lab Director Pete Nanos' latest action brings to 23 the number of employees suspended in the wake of a security and safety scandal that has brought a halt to classified work and cast doubt on the future of the 61-year-old lab.

Last month, Nanos suspended 19 workers: 15 in connection with the missing disks and four others as part of a probe into how a lab intern suffered a serious eye injury from a laser. The workers have been stripped of their badges until the inquiries are complete.

Nanos spent much of Wednesday with leaders of the University of California, which manages the nuclear facility, who took part in an "all-hands" meeting with the 12,000-strong work force.

UC President Robert C. Dines (search) spoke to the workers about the lab's problems, telling a packed auditorium: "I need you to help me help you."

After a similar "all-hands" meeting last month, Nanos had complained that some lab workers weren't taking problems at the lab seriously. But Wednesday, Nano said: "I think the realization of this has really taken root."

Beyond announcing the latest suspensions, Nanos was mostly tightlipped on the probe into the missing disks. The disks were discovered missing July 7, prompting a halt a week later to nearly all work at the facility.

The FBI (search) since has been called in but Nanos declined to comment on their role or whether criminal charges are possible.

"I don't want to put anything out I can't stand behind," he said.

Although classified work remains idled, Nanos said that as of Wednesday about three-quarters of the lab's administrative office tasks were back in operation. In addition, an inventory of the lab's portable data storage devices, such as computer disks, is 90 percent complete.

Returning the lab to normal is expected to take another two months, Nanos said.