French prosecutors want a Franco-Algerian nuclear scientist to spend six years behind bars.
Adlène Hicheur, who worked at the CERN research centre in Geneva, Switzerland, is on trial in Paris on charges of criminal association as part of a terrorist entreprise.
Police arrested him after intercepting emails he wrote to an alleged al-Qaeda contact.
Hicheur has spent the past two years in custody awaiting trial.
His lawyer Patrick Baudouin said of the e-mail exchange:
"The prosecutor tried to prove those words were actually showing an intention to concretely act, helping to prepare or directly preparing a terrorist action. This is exactly what I contested, because Adlène Hicheur's words hadn't mentioned any precise planning of anything in particular."
When asked by euronews if police had identified the alleged Al-Qaeda contact, he said:
"This person has not been formally identified, but throughout the investigation they said it appears to be Mustapha Debchi, who is allegedly a senior member of Al-Qaeda in the Islamic Maghreb, based in Algeria. "But if you are sure about his identity, you don't say 'it appears to be' -- you say it is that person in question."
Hicheur's trial comes more than one week after French president Nicolas Sarkozy proposed to make repeated surfing of extremist websites a criminal offence following the Toulouse shootings.