Three people were present when Eskom employee Thembisile Yende was murdered, the investigating officer in the case testified in the Springs Magistrate's Court on Monday during the bail application of the man accused of killing her.
David Ngwenya, 43, appeared in court on charges of premeditated murder, with the state arguing that the case should be viewed as a schedule six offence.
Ngwenya, who confirmed in an affidavit read out in court on Monday morning that he is an Eskom employee, has denied that he committed premeditated murder.
Colonel Christo Lotz, the investigating officer, said there was allegedly a copper theft syndicate, and the suspect and two others were worried that police would be on their case if this information surfaced, as Yende was allegedly a whistleblower.
According to Lotz, Ngwenya spoke to three people before the murder in order to tell them that Yende was allegedly a whistleblower.
Two other people were allegedly present when Yende was murdered, with the investigating officer saying that Yende was injected and taken to the Pietersboth substation, where she was hit on the head and murdered.
The murder was allegedly staged to look like a suicide.
The state opposes Ngwenya's release on bail and on Monday wanted his bail application postponed due to outstanding documents.
The defence did not want a postponement.
Magistrate Cornell Pretorious denied the postponement.
Ngwenya, who is married with three children and works as a technician at Eskom, was arrested in Carletonville, west of Johannesburg last Thursday.
The suspect was identified by a witness in an identity parade, and the same witness revealed that Ngwenya was allegedly in a romantic relationship with Yende.
Yende's body was found in an office at the isolated Eskom Pietersboth substation in Springs, Ekurhuleni in late May, after Eskom workers picked up a rancid smell over a week after she was reported missing.
The 29-year-old mother of one was reported missing on May 17.
A post-mortem has shown that Yende - who had been an employee of Eskom since December 2015 - had sustained head injuries and had bruises on her neck before she died.
When she arrived at work on the morning of her disappearance, the closed circuit camera picked her up, but moments later, there was no movement traced by the camera.
Ngwenya is to remain in custody for now, with concerns that he will not be safe should he be released.