The family of slain Eskom employee Thembisile Yende, who was found dead at a substation in Ekurhuleni last year, has accused the power utility of shielding her killer.

Yende's brother, Mboneni Yende, yesterday told Sowetan his family was disappointed that charges were provisionally withdrawn against her alleged killer, David Ngwenya.

"We are very disappointed at Eskom because we believe they didn't do much to help find her killers. Her body was discovered at her workplace and yet Eskom has failed to give enough evidence to police," he said.

Yende said they believed someone at management level at Eskom knew who killed Thembisile.

"Police told us there was a witness and recently when we asked about the witness we were told that the person had mysteriously disappeared. We urge the police to investigate thoroughly until they find my sister's killers," he said.

However, Eskom spokesman Khulu Phasiwe said they had been cooperating with the police.

"We have given the police video footage of when she entered the substation and assisted with every police inquiry. We will continue to work with the police any time they need assistance from us," he said.

Phasiwe said they understood the family's frustration.

"We also want to see the police cracking this case because it's a year now and the person who was suspected of her murder has been released," he said.

Ekurhuleni East police spokesman Captain Johannes Ramphora said investigations were continuing in the matter.

National Prosecuting Authority spokeswoman Phindi Mjonondwane was not immediately available for comment.

The state alleged at the time of Ngwenya's arrest that Thembisile was killed because she knew of his alleged copper dealings and was about to report his activities to managers.

Her decomposed body was found at Pietersboth electricity supply substation days after her disappearance..

Ngwenya's lawyer, advocate Zola Majavu, said the withdrawal was expected.

"The state had no evidence against our client to begin with. This was also confirmed through DNA report obtained by the prosecution and shared with us.

"Our client always maintained his innocence and based on the information at our disposal, we had no reason to gainsay that.

"We are also mindful that the state reserves the right to resume the prosecution should it come by some tangible evidence against our client," Majavu said.

He said for now Ngwenya was a free man.

"And we are happy for him after this year-long ordeal, having spent six months behind bars after being denied bail. We secured his release on bail after a high court appeal in December 2017."

"Our client continues to respect the rule of law and will subject himself to any judicial processes."