A nuclear physicist working at the world's largest atom smasher has been arrested on suspicion of links to the Algerian branch of Al Qaeda, another blow to a project that has been plagued by glitches and was shut down after a massive electrical failure a year ago.

The scientist, arrested in France, is suspected of having links to Al Qaeda's North African offshoot, which has carried out a deadly campaign against security forces in recent months, a French official said Friday.

The judicial official said the suspect was one of two brothers arrested Thursday in southeastern French city of Vienne. The official spoke anonymously because the case is ongoing.

The scientist has been assigned to analysis projects at the laboratory since 2003, and was one of more than 7,000 scientists working on the Large Hadron Collider, the world's largest atom smasher, said the European Organization for Nuclear Research, known as CERN.

The physicist had no contact with anything that could be used for terrorism, it said.

"None of our research has potential for military application, and all our results are published openly in the public domain," the organization said.

The LHCb experiment where he worked is the smallest of a series of installations along the 17-mile circular tunnel under the Swiss-French border.

The nuclear research organization said the man, whom it did not identify, was arrested Thursday in the eastern French city of Vienne, 20 miles south of Lyon.

The men were French and aged 25 and 32, police said. The arrest was part of a French judge's probe into suspected terrorist links.

Police searched the suspects' apartments and seized their computers.

Al Qaeda in Islamic Maghreb regularly targets Algerian government forces and occasionally attacks foreigners.

The collider started spectacularly in September 2008 with beams of particles flying in both directions on the first day of trying. But later that month an electric failure because of a construction fault caused the entire machine to shut down. It has been undergoing repairs almost ever since.

Spokeswoman Renilde Vanden Broeck said there was no indication of sabotage in the shutdown and that the arrested man would have had access only to the small experiment he was working on, and not to the tunnel itself.

The projects are aimed at making discoveries about the makeup of matter when the Large Hadron Collider starts collecting data later this year or early next year.

"LHCb is an experiment set up to explore what happened after the Big Bang that allowed matter to survive and build the universe we inhabit today," said a description on the organization's Web site.

The Big Bang was a vast explosion that scientists theorize was the beginning of the universe 14 billion years ago.

The European laboratory has been working for years to build the $10 billion collider.

Not all physicists working on the LHCb project were informed of the arrest.

"This is news to me," said Ken Wyllie, one of dozens of scientists in the department.

The prosecutor's office in the Isere region said the arrest of the physicist had been transferred to the anti-terrorist section of the Paris prosecutor's office.

Many of the scientists at the laboratory, whether or not they are employees of the organization or of other institutes around the world, live in France, and about half the operation is on French territory.

The nuclear research organization said the man was affiliated with an outside institute.

The laboratory said it is providing the support requested by the French police in the inquiry.