Four men convicted in the fatal gang-rape of a 23-year-old student in the Indian capital are due to be sentenced on Friday.

The four men, aged between 19 and 26, face a minimum punishment of life imprisonment and a maximum of the death penalty.

A special court on Tuesday found the four men guilty of rape, unnatural sexual offences and of murdering “a helpless victim.” Judge Yogesh Khanna, after hearing arguments on sentencing on Wednesday, said he would pronounce sentence on Friday.

The prosecution has described the crime as diabolical and said it deserved nothing less than the death penalty.

The defence has pleaded for a lesser sentence due to the age of the convicted men, saying there was a possibility of rehabilitation.

Defence lawyers have said they would appeal against the conviction in a higher court, alleging gaps in the evidence and that their clients had been tortured by the police and forced to confess.

The student was repeatedly raped and brutally beaten in a moving bus in the Indian capital on December 16 and died 13 days later.

Six people, including a juvenile were charged in the case. The main accused, Ram Singh, was found hanged earlier this year in his jail cell and the case against him was dropped.

The juvenile was tried by a separate court and sentenced to three years in a correctional facility.

The December gang-rape led to huge protests in India and prompted the Government to change laws introducing stricter punishment for rape.