Dr. Abdullah al-Shaleef told the Yemen National Monday he believed the Central Security Forces and Republican Guards were guilty of torture, unlawful arrests and other abuses at facilities in Arhab and Nehm, villages on the outskirts of the capital of Sanaa.
There was no immediate comment from prison authorities.
Al-Shaleef said some torture was so severe prisoners were driven to madness.
He said the organization sent investigators to interview families of prisoners to collect evidence.
Al-Shaleef told the Yemen National he would take the matter up with Human Rights Minister Oooria Mashour.