A documentary challenging the case against honeymoon murder accused Shrien Dewani will air on Thursday night, despite outrage from his former bride's family.
BBC Panorama is set to raise concerns about the prosecution case against the 33-year-old businessman, who is accused of ordering the murder of his wife in South Africa in 2010.
Anni Dewani, 28, was shot in the neck as the couple travelled in a taxi on the outskirts of Cape Town. The documentary suggests that she could have been shot by mistake in a struggle, and that there are significant contradictions in the account given by the taxi driver Zola Tongo. It also claims that a soundtrack obtained from CCTV shows that hotel receptionist Monde Mbolombo, who has been granted immunity from prosecution, could have played a key role in what happened.
Professor of forensic science Jim Fraser told the programme: "This is not an investigation that would meet the standards in this country. This is not what would be considered to be good practice. There are many things... that fall a long way short of effective investigation."
The documentary team has accessed police files that make up the prosecution case against Dewani. The material reveals that CCTV and phone records appear to contradict parts of the account given by Tongo, who was jailed for 18 years after he admitted his part in the killing. This includes a call he claimed to have received from Dewani on the day of the murder, that did not happen.
Xolile Mngeni, who prosecutors claim was the hitman, was convicted of premeditated murder for the shooting, and another accomplice, Mziwamadoda Qwabe, also pleaded guilty to murder and was handed a 25-year prison sentence.
Mbolombo claimed that he had put Tongo in touch with the gunmen, but had no further involvement - however questions have been raised over comments he was recorded making. The Mail on Sunday revealed that in an audio track that has been enhanced from CCTV, he says: "This is how it's going to happen. Listen, don't give them it all up front. Give them what you've got on you so they don't come crying to you."
South African investigators believe Anni was cowering against the back seat when she was deliberately shot from a distance of two inches to four inches (5cm - 10cm) away. But firearms expert Mark Mastaglio told the programme that a wound in Anni's hand suggests she was shot at very close range, less than two inches away, and that he believes the gun went off in a struggle. Home Office Pathologist Dr Richard Shepherd said there would have been blood spatter on the seat had Anni been cowering back against it, and that he believes she was leaning or sitting forward.
Anni's uncle, Ashok Hindocha, who has written to BBC Director General Tony Hall and the BBC Trust to express his concerns about the documentary, said the issues should be tackled in court rather than on television. He said: "This is confidential material. We welcome any kind of investigation telling us what happened to Anni, but is a TV studio the right medium to conduct such a case? No. They are questioning the South African police, but who's going to cross-examine the experts they hired? I'm sure they can't be 100% right. It's for the courts to decide."
The Honeymoon Murder: Who Killed Anni? will air at 9pm on Thursday on BBC One.