The trial of Shrien Dewani, 34, will begin at South Africa’s Western Cape High Court. He was extradited from Britain in April and was held at Valkenberg Hospital in Cape Town to ascertain whether he was mentally fit to stand trial.
Dewani has pleaded not guilty to the murder charges.
Dewani and his wife Anni were held at gunpoint while being driven in a taxi through Gugulethu township near Cape Town in November 2010.
Dewani was thrown out of the car later that night and the body of Anni Dewani was found the next day with a single gun shot wound on her neck.
Three men have been convicted in South Africa in the case: Xolile Mngeni, who was found guilty of shooting Anni, taxi driver Zola Tongo, who admitted to his part in the killing, and Mziwamadoda Qwabe, another accused who has also pleaded guilty to Anni’s murder.
Dewani was detained in Britain under the Mental Health Act after being diagnosed with severe depression and post-traumatic stress disorder.
The family told BBC’s Asian Network they would be unable to grieve until they learned the truth.
Shrien Dewani, 34, from Bristol, is accused of hiring a hitman to murder his wife. He denies any involvement.
Mr Dewani was extradited to South Africa in April after a three-year legal battle.
His legal team argued that his mental health was too fragile for him to stand trial.
Anni Dewani was shot dead in Cape Town in November 2010, just days after the couple’s wedding in India.
The trial is due to begin on Monday and is expected to last two months.
Three men are currently serving jail terms in South Africa in connection with the death of Mrs Dewani, including taxi driver Zola Tongo, who was jailed for 18 years after admitting his role in the killing.
Xolile Mngeni, who prosecutors claim was the hitman, was convicted of premeditated murder over the shooting.
Another accomplice, Mziwamadoda Qwabe, pleaded guilty to murder and was handed a 25-year prison sentence.
Nilam, 62, who is in remission from cancer, has vowed to be in Cape Town throughout the trial.
She says: “We know it is going to be torture hearing the details of Anni’s death, but we will be in court every day.
“We know it’s going to be very difficult but we will do anything to get justice. People say time heals wounds, but in our case, the wounds are deeper the longer we live without answers.
“Once this is over, we hope we can move forward with our lives and our Anni can finally be at peace.”