Updated

One of two South African men accused of being hired by a British newlywed to kill his Swedish bride pleaded guilty Wednesday to his involvement in the slaying and received a 25-year prison sentence after promising to cooperate with prosecutors, officials said.

Mziwamadoda Qwabe pleaded guilty to charges of kidnapping, robbery, murder and illegal possession of a firearm at a hearing in the Western Cape High Court over the November 2010 killing of Anni Dewani. Judge John Hlophe accepted Qwabe's plea bargain, which came as prosecutors and defense lawyers met to prepare for the scheduled start of his trial Monday with accused accomplice Xolile Mngeni, a court official said.

Qwabe's deal requires him to cooperate and testify against others accused in the case, including Dewani's husband, Shrien, who is accused of hiring the two men to kill her on their honeymoon, said Eric Ntabazalila, a spokesman for South Africa's National Prosecuting Authority.

Lawyers and prosecutors also met Wednesday with Mngeni, Ntabazalila said. Mngeni will appear Monday in court, though it is unclear whether his trial will begin then, the spokesman said.

A lawyer for Qwabe could not be immediately reached for comment.

Qwabe and Mngeni's trial has been postponed several times due to Mngeni's poor health. Mngeni had surgery to remove a brain tumor in June 2011.

The Dewanis were honeymooning in South Africa in November 2010 two weeks after their marriage. Anni Dewani's body, shot in the back of the neck, was found in an abandoned taxi in Cape Town's impoverished Gugulethu township. Husband Shrien Dewani later told investigators gunmen forced him and a taxi driver from the car when they were taking a tour.

Officials at first thought the crime was robbery in South Africa, where violent crime is high but attacks on foreign tourists are rare. However, taxi driver Zola Tongo later testified that Shrien Dewani offered him 15,000 rand (about $2,100) to arrange the killing and make it look like a carjacking. In a plea bargain to avoid a life sentence, Tongo pleaded guilty and was convicted of kidnapping, murder, aggravated robbery and obstructing justice. He was sentenced to 18 years in prison, and is expected to give evidence at trial.

Dewani denied he hired anyone to kill his wife and was allowed by authorities to leave South Africa for the United Kingdom, where he was later arrested. In March, a U.K. High Court ruled that it would be "unjust and oppressive" to extradite Dewani to South Africa, as his mental condition had worsened since his arrest there. Dewani's lawyer told the court in a hearing July 31 that he needed at least a year to recover from depression and post-traumatic stress disorder before being potentially sent back to South Africa.

Ashok Hindocha, Anni Dewani's uncle, said her family was pleased by Qwabe pleading guilty, but "want to know what really happened."

"The way we feel is that we are going through legal torture," Hindocha told the U.K. Press Association. "It is extremely stressful for the family."