The family of the deceased N Dhamendran has claimed harassment by the police and Prime Minister's department.
However, Minister in the Prime Minister's department Paul Low has denied the allegation.
Media reports quoted local opposition politician N Surendran as saying that injuries found on the body included staple wounds and bruises on the front and back of the body and legs.
Dhamendran, 32, died while he was detained at the Kuala Lumpur police headquarters on May 21. He had complained of chest pain and was sent to a city hospital but died on arrival, reports said.
"We have a post-mortem report from forensic expert which stated that the cause of my husband's death was multiple blunt force trauma. Why are they still calling up my family and even my lawyer? They haven't even arrested a single cop responsible," she was quoted by media reports as saying.