A police captain on Wednesday denied claims that a video of the apparent confession by Anni Dewani's alleged killer was doctored.
In a trial within a trial in the Western Cape High Court, lawyers representing Xolile Mngeni disputed his 2010 statement to police.
They claim Mngeni was assaulted and told what to say by officers.
Police captain Adolf Jonker disputed Mngeni's claim that the video with his alleged confession was tampered with.
According to Mngeni's lawyer, footage of the police telling their client what to say has been excluded.
Mngeni also claims he was not allowed to request a lawyer.
Jonker said there was nothing suspicious about the video, adding it had not been edited.
However, a policewoman, who transported Mngeni to and from the confession room, then testified she never saw officers entering the room where he gave his statement.
Earlier, Mngeni claimed his testicles were put into a desk drawer and slammed while he was in police custody.
He also allegedly suffered a blackout while in custody at the Bellville police station.
On Tuesday, Mngeni denied firing the fatal shot the killed the British tourist.
He shifted the blame to his co-accused, Mziwamadoda Qwabe, who is serving 25-years for his role in the crime.
Qwabe told the court they were paid by Anni's husband, Shrien Dewani, for the murder.
Dewani is reportedly suffering from post-traumatic stress disorder following his wife's death in November 2010.
The National Prosecuting Authority (NPA) wants him extradited to South Africa to face murder charges.
Dewani denies any involvement in the murder.