Chad’s ex-President Hissene Habre has gone to court to challenge his conviction for crimes against humanity.
His lawyers argue that the trial by a special court jointly set up by Senegal and the African Union was marred by procedural errors.
They also say the defendant’s rights were not respected.
Mr. Habre was the first former leader to be convicted by an African Union-backed court - his case was seen as a landmark for the continent.
The former president ruled Chad from 1982 until he was overthrown in 1990 and fled into exile in Dakar, the capital of Senegal.
He was sentenced to life in prison after being convicted of rape, sexual slavery and ordering mass killings.