A French court has sentenced a scientist at the prestigious Cern laboratory to five years in prison for plotting terrorist attacks.

Adlene Hicheur was arrested in 2009 after police intercepted his emails to an alleged contact in al-Qaeda.

The emails suggested Algerian-born Hicheur was willing to be part of an "active terrorist unit", attacking targets in France.

Defence lawyers argued that their client had never been part of a plot.

Hicheur, who is a particle physicist, worked as a researcher studying the origins of the universe at Cern.

His father embraced him in the Paris courtroom before he was taken away to prison.

Hicheur has already spent two and a half years in jail while awaiting trial.

He came under suspicion when threatening messages were sent to President Sarkozy in early 2008.

The security services uncovered a series of email exchanges between Hicheur and an alleged al-Qaeda member called Mustapha Debchi.

After his arrest in 2009 police found a large quantity of Islamist literature at his parents' home.

At the start of his trial he admitted that he had been going through a psychologically "turbulent" time in his life when he wrote the emails, but always denied he intended to carry out any attacks.