One of Tunisia's most prominent opposition leaders, Rached Ghannouchi, has been sentenced to 14 years in prison.

The 86-year-old's sentencing follows an alleged involvement in conspiring against state security.He has been charged in several other cases, including money laundering for more than 20 years.

In a statement, Ghannouchi's defence team debunked the claims, describing the court's judgement as false and unfair.

“All accusations were based on a false and contradictory testimony by a secret, anonymous witness who failed to present any evidence for his baseless and contradictory allegations, and who ultimately retracted most of them,” attorneys said in a statement.

Rached Ghannouchi, who doubles as the leader of Tunisia's Ennahda movement, has faced prosecution since President Kais Saied took power six years ago.

Tunisia's Arab Spring revolution, which unseated a decades-long regime, ushered in his party's rise to prominence.

Twelve-year sentences have also been issued to other detained members of Ghannouchi’s party.

The victims include Ghannouchi's son and a former foreign minister.

They have been charged for participating in terrorist acts, inciting violence, attempting to overthrow the government.

The defendants have also been accused of recruiting and training individuals within Tunisia and abroad for terrorist purposes.