French police have arrested an engineer who worked at Cern, Europe's Switzerland-based nuclear research organisation, on suspicion that he had links to al-Qaida in Algeria.

One of two French-Algerian brothers, aged 25 and 32, arrested yesterday in Vienne, south-east France, was an engineer at the nuclear research centre on the French-Swiss border just outside Geneva, it emerged today.

The men were arrested on suspicion of being in close contact with al-Qaida in the Islamic Maghreb (AQIM), also known as al-Qaida's north African wing.

Le Figaro reported that the older brother who worked at Cern, famous for its particle collider that aims to recreate the conditions of the Big Bang, had been in contact with AQIM and had suggested French targets for attacks.

A judicial source confirmed that one of the brothers had been in contact with people close to the organisation but said there was no indication of a clearly established plot at this stage.

Cern issued a statement saying the man was a physicist who had worked at the centre since 2003, specialising in physics data analysis.

The organisation said he had "never been in contact with any element that could be used for terrorist ends" and no research at Cern was used for military applications. The physicist was not employed by Cern but was a contractor with another institute.

The European laboratory which specialises in high-energy particle physics is famous for what has been dubbed the world's biggest science experiment, the Large Hadron Collider which was intended to recreate the conditions of the origin of the universe but hit difficulties days after being started up.

AQIM, al-Qaida's north African wing, has claimed responsibility for a suicide bombing at the French embassy in Mauritania, that wounded three people in August.