The wife of Rafael Acosta, who died after being detained on conspiracy accusations, said earlier on Monday the United Nations should investigate the cause of his death, amid widespread accusations he was tortured to death.

"I urge the authorities to conduct an in-depth investigation - including an autopsy meeting international standards - that is both independent and transparent.

This is essential to shed light not only on what happened to him, but in order to facilitate bringing to justice those responsible for his death," Bachelet said in a statement issued in Geneva.