Officers from the Metropolitan Police's extradition unit detained Shrien Dewani, 30, on behalf of the South African authorities.
He surrendered himself to the police in Bristol and was arrested on Tuesday night.
Shrien was arrested under a Provisional Arrest Warrant for suspicion of conspiring to murder Anni, 28. Shrien is accused of conspiring with others to murder Anni on November 13.
He is due to appear in custody at City of Westminster Magistrates' Court on Wednesday
Shrien, a businessman, now faces being extradited to South Africa after prosecutors there claimed he had offered to pay 1,300 pounds to have his wife murdered on their honeymoon.
He allegedly offered money to a taxi driver to arrange for Anni to be shot dead in a staged carjacking in a township, according to claims outlined by a prosecutor.
Shrien, who owns a chain of care homes, dismissed the accusations as 'ludicrous'.
The two were traveling through Gugulethu, a township, when they were ambushed by two men who appeared to threaten their driver, Zola Tongo, and ordered him out of the car before also ejecting Anni.
She was found shot dead in the back of the car several hours later.
On Tuesday, prosecutors in South Africa publicly accepted a signed confession from Tongo that was agreed as part of a plea bargain deal in which he admitted murder, aggravated robbery and kidnapping.
With Anni's father, Vinod Hindocha, and other relatives who had flown in from Sweden, looking on, Rodney de Kock, the Western Cape director of public prosecutions, said Shrien had orchestrated the murder.
He told Judge John Hlophe, "The alleged hijacking was in fact not a hijacking, but part of a plan of subterfuge which Shrien Dewani, the husband of the deceased, and the accused had designed to conceal the true facts, to wit: that the deceased was murdered at the instance of her husband."
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