A lawyer said Mr Larayedh, who is also a senior figure in the Islamist opposition Ennahda party, had been questioned for hours.

In a statement, Ennahda denounced this as a flagrant violation of human rights.

Prty leader Rached Ghannouchi is due to be questioned later on Tuesday.

Ennahda rejects the charges.

President Kais Said has tightened his grip on the judiciary following his suspension of the Ennahda-dominated parliament last year.