The US Department of Energy has fined the University of California $3 million for violations related to a security breach at Los Alamos National Laboratory in New Mexico.

In a raid in 2006, police found classified material in the home of a subcontractor who had been scanning lab documents for a work project. The department determined that the University of California's security measures were ?deficient? and partly to blame for the violation.

Los Alamos has been hit by a series of security lapses in recent years, causing the energy department to sever an exclusive contract with the University of California that dated back to the Second World War. Since June 2006 the university has managed the lab as part of a broader business consortium.

Spokesman Chris Harrington says that the university is reviewing the final notice and has not yet determined whether to appeal against the ruling.