Johannesburg - Convicted murderer Oscar Pistorius is serving his six-year sentence for killing his girlfriend in a single hospital prison cell, an official said on Thursday.The disgraced paralympian is in the same cell in Pretoria's Kgosi Mampuru prison he was previously incarcerated for one year. Manelisi Wolela, spokesperson for the Department of Correctional Services, said the special accommodation was due to his disability and that the prison had never had a double amputee inmate before."He is in the same facility in the hospital section of the Pretoria prison," Wolela told AFP. Wolela said the hospital wing of the prison had a number of other prisoners, some of whom are sick or disabled."If you expose them to communal normal cells, they will be vulnerable," he said.Pistorius, 29, began his sentence on Wednesday after he had his conviction of manslaughter was last year upgraded to murder for shooting dead his girlfriend Reeva Steenkamp three years ago.His lawyers said he won't appeal the sentence, which is just one year longer than his earlier jail term.He is eligible for parole after serving between half to two-thirds of his sentence.