The gendarme police prevented Huseyin Cangir, the head of IHD's Mardin branch, from entering the village.
Cangir was going to the village to meet the relatives of the victim and speak to witnesses.
A group from the German Socialist Democrat Party (SDP), who was in the region for Newroz celebrations, and officials from Democratic People's Party (DEHAP) were also prevented from visiting the victim's family.
Perincek, who could only meet with Ersin Eroglu, the head official of Nusaybin, said the paramilitary police didn't give a reason for blocking them from entering the village and asked for a written application for entrance permission.
"Rights violations, and efforts to cover up those violations have heightened recently," said Perincek. "We are calling on all officials, and especially the government, to seek legal action against all those responsible," said Perincek. (EU/EA/YE)