Suaram has called for the resignation of Home Minister Ahmad Zahid Hamidi after the fourth custodial death this year despite promises to address the problem.
"There can be no more compromises on custodial death cases as the numbers have reached a worrying level.
"Without clear efforts by the authorities (to address the issue), the home ministry should relinquish his position," said Suaram executive director D Sevan.
Sevan said the latest death happened on March 20 where 30-year-old R Siva who was due to be released from Tapah prison the next day died from an infection.
"This could have been avoided if the victim received early treatment for his complication.
"The victim was only brought to Tapah Hospital after he died," he said.
Suaram reiterated that the authorities are responsible for the health of detainees.
Sevan added that the family complained that they were not informed of the death before the post-mortem.
The post-mortem concluded that he died from an infection from a wound on his leg.