By Daniel Schweimler
BBC News, Buenos Aires
The wife and two grown-up children of a convicted human rights abuser in Argentina have been arrested in connection with his death.
Argentina's period of military rule is still a contentious issue
Hector Febres was found in his cell earlier this week having ingested cyanide, just days before he was to be sentenced for human rights abuses.
The crimes were committed under military rule in the 1970s and '80s.
An estimated 30,000 people were kidnapped, tortured and killed during Argentina's "dirty war" from 1976-1983.
Hector Febres worked at the Naval Mechanics School, or ESMA, the most notorious detention and torture centre used under Argentina's military rule.
Many died there, their bodies thrown into the nearby River Plate.
Febres had stories to tell and many suspected he might talk before being sentenced.
Thousands of people "disappeared" under Argentina's military rule
Police are investigating whether he was murdered or he killed himself.
Prosecution lawyers are convinced he was silenced by those linked to the military who kidnapped, tortured and killed an estimated 30,000 people during military rule.
Two of those responsible for guarding Febres have been detained. So have his wife and two grown-up children, who ate with him the night before his body was found poisoned with cyanide.
Febres was to be the first person from the ESMA to be sentenced, but the legal process will end with his death.
The detention centre was earlier this year handed over to the civilian authorities and will become a memorial centre or museum.
But the families of the victims will feel that the death of Febres has robbed them of an opportunity to find out more and to see justice done in Argentina - a process which has so far moved very slowly.