Nuclear engineer from Cern lab arrested for al-Qaeda links

French agents have arrested a researcher from Europe's top atomic lab on suspicion of links to al-Qaeda, fuelling fears that terrorists could be targeting the nuclear industry.

The 32-year-old man, who was detained along with his brother, works for the prestigious European Organisation for Nuclear Research (Cern) in Geneva, Switzerland, according to French police sources.

''The inquiry will doubtless say what were the objectives in France or elsewhere and indicate perhaps that we have avoided the worst possible scenario,'' said Brice Hortefeux, the French Interior Minister.

An intelligence source told Le Figaro that ''this is a very high level'' case.

The suspect is believed to have been in contact with members of al-Qaeda in the Islamic Maghreb (AQIM), an Algerian-based terrorist organisation which joined Osama bin Laden's network in 2007.

A source said French intelligence officers had intercepted messages in which the man had suggested targets in France.

''He had expressed a wish or a desire to commit terrorist actions, but had not materially prepared them,'' said the source.

The suspect had been under surveillance for about 18 months after he was identified during an investigation into a French network which sent Islamic radicals to Afghanistan.

Judge Christophe Teissier, an investigating magistrate specialising in the fight against terrorism, opened a formal inquiry last month into his activities.

The man was arrested on suspicion of involvement in a criminal association linked to a terrorist undertaking by the Central Directorate of Interior Intelligence (DCRI) at his home in Vienne, eastern France.

His 25-year-old brother was also arrested as police seized two computers, three hard discs and two USB keys at their home.

Both men were taken for questioning at the DCRI headquarters in Levallois-Perret outside Paris.

The arrests fuelled concern in France that al-Qaeda's north African wing could launch a campaign on the French side of Mediterranean.

Mr Hortefeux was quick to recall that AQIM had threatened French interests.

''We are in a situation of permanent vigilance and we follow the declarations of the leaders of certain organisations day by day,'' he said. ''Our vigilance is never lowered. The risk is permanent.''

Cern said the suspect had "never been in contact with any elements which could be used for terrorist purposes."

He was a physicist who worked on data analysis "in the context of a contract with another institute" and "none of his research had a potential military application", it said in a statement.

Previously known as the Salafist Group for Preaching and Combat, AQIM waged a war with the Algerian authorities in a bid to install an Islamic state at the cost of tens of thousands of lives in the 1990s.

But since joining al-Qaeda it has spread its activities to neighbouring countries such as Mali, Niger and Mauritania.

In June it claimed responsibility for the killing of Christopher Leggett, an American humanitarian worker, in Mauritania.