Warrant Officer David Shivambu testified that the police found Thabiso Malatji, 23, who is mentally unstable, on top of his grandfather's decomposed body eating worms.

A man was found on top of his grandfather's decomposed body eating maggots, the Atteridgeville Magistrate's Court heard on Wednesday.

Warrant Officer David Shivambu testified that the police found Thabiso Malatji, 23, who is mentally unstable, on top of his grandfather's decomposed body eating worms.

State prosecutor Ernest Mbembele described this as "disgusting".

Samuel Malatji, Regina Malatji and Lillian Malatji face charges of murder, kidnapping and defeating the ends of justice.

They were arrested for allegedly locking their father Benedict Malatji, 80, and two of their nephews, Thabo and Kentridge Malatji, 30, in a room for more than a year at their family house in Atteridgeville, west of Pretoria.

Defence advocate Justice Mnisi argued that the State's case was weak and was based on the testimony of Kentridge Malatji.

He escaped from the room, which had security bars, leaving behind his brother with his dead grandfather.

Mnisi disputed claims that the three were kidnapped, and said Kentridge had his cellphone all along and even called some of his family members.

"The accused should be granted bail as they need to make funeral arrangement for their father, said Mnisi.

All three were denied bail.