Missing hard drives with nuclear secrets found at Los Alamos.(Chicago Tribune)

WASHINGTON _ Officials found two computer hard drives at the Los Alamos National Laboratory on Friday in "questionable circumstances," ending an intensive search for the highly classified computer files but not the inquiry into how they became lost and whether the nuclear secrets they contained fell into the wrong hands.

The Department of Energy said in a statement that officials found the missing hard drives within the secure confines of Los Alamos' "X Division," the area of the New Mexico lab involved in the design of nuclear weapons.

A government official familiar with the investigation said the way in which the hard drives turned up raises suspicion among investigators that a Los Alamos staffer who had improperly taken the disks returned them to the lab, to a location where they would quickly be found.

"The hard drives were found in what appeared to be questionable circumstances," said the official, who spoke on condition of …