The country’s attorney general has opened an investigation into the former CERN physicist arrested in France last month.

The investigation is based on allegations of the man being involved with a criminal organization, according to officials. The man was charged last month in Paris for “criminal associations with a terrorist enterprise.”

The man is accused of having links with Al-Qaeda in Islamic Maghreb, and is suspected of having planned to commit an attack in France

Swiss officials say a crime committed abroad, but planned in Switzerland, is punishable in Switzerland.

If he’s found guilty of planning a violent crime, the former CERN worker could spend up to five years in prison.