A rights activist in Russia's North Caucasus region of Ingushetia says investigators accompanied by masked officers searched his home on June 30.
More than 20 law enforcement agents were involved in the early-morning search at the home of Magomed Mutsolgov, head of the Mashr (Peace) human rights organization, the group said on its website.
The organization did not indicate the reason for the search, and investigators did not immediately release details.
The Russian-language news portal Caucasus Knot (Kavkazsky Uzel), which publishes critical coverage of authorities in the region, cited an unidentified source as saying Mutsolgov had been contacted by prosecutors in Ingushetia days earlier over the blog he writes for the website.
Caucasus Knot was established by the rights group Memorial in 2001 and mainly covers Russia's North Caucasus, nearby regions in southern Russia, and the South Caucasus countries of Armenia, Azerbaijan, and Georgia.
Mutsolgov wrote in a blog post for the site later on June 30 that the law enforcement officers conducted themselves "appropriately" during the search and did not "plant" any evidence.
Mashr, established in April 2005 by the relatives of kidnapped or missing residents of Ingushetia, is one of the few nongovernmental organizations in Russia's North Caucasus that monitors human rights abuses in the volatile region.
Russia's Justice Ministry in 2015 placed the group on its official register of organizations "operating as foreign agents."
A Russian law adopted in 2012 requires any nongovernmental organization that receives funding from abroad and engages in political activity to formally register as a "foreign agent."