The man convicted for the murder of a woman killed on honeymoon in Cape Town has died, announced South Africa's Department of Correctional Services.

Xolile Mngeni, who was convicted for the murder in 2010 of Anni Dewani, died in a hospital unit of a Cape Town prison.

South African prosecutors argue that the woman's husband, Shrien Dewani, conspired with Mngeni and two other men to kill his wife.

Dewani, who has pleaded not guilty to charges ranging from murder to kidnapping, said he and his wife were hijacked at gunpoint while on a nighttime drive through a Cape Town township. Dewani said he was forced out of the car and the alleged assailants drove off with his wife still in the backseat of the car. The car and the body of Anni Dewani were found the next day.

Mngeni, who was convicted as the man who fired the gun that killed the 28-year-old Swedish national, was serving a life sentence when he died. Mngeni was diagnosed with a brain tumor during his murder trial in 2011. The Cape Town local applied for medical parole in July this year but it was denied.

Earlier this month, another man convicted for the murder, Mziwamadoda Qwabe testified that he was hired by the Dewani's taxi driver, Zola Tongo, to kill Anni Dewani. Qwabe and Tongo are currently serving long prison theories for the killing.

Dewani is standing trial in South Africa after fighting extradition from the United Kingdom for nearly four years.

Mngeni has been a figure during the ongoing trial.