David Ngwenya is due to appear in the Springs Magistrate's Court on Monday in connection with the murder of Eskom employee Thembisile Yende.
Ngwenya, 43-year-old technician at Eskom, stands accused of injecting his lover Yende with a substance before striking her head with a crowbar and subsequently suffocating and strangling her after a struggle.
This allegedly after he suspected that she would "spill the beans" on his involvement in a copper cable theft syndicate.
Yende, a 29-year-old mother of one, went missing on May 17. Her body was found in an office at the isolated Eskom Pietersboth substation in Springs, Ekurhuleni, after Eskom workers picked up a putrid smell over a week after she was reported missing.
Ngwenya was arrested on June 15.
He was denied bail in late June. When he last appeared in court, on 17 July, the case was postponed for further investigation.