Galina Kozhevnikova, a rights activist and leading researcher on nationalism and xenophobia, died of cancer Saturday at the age of 36.
A funeral will be held Wednesday and will be closed to the public, Interfax said, citing her colleagues.
Kozhevnikova, who was to turn 37 next Wednesday, was a co-founder and deputy director at the Sova think tank, created with the help of the Moscow Helsinki Group in 2002.
A graduate of the Moscow-based Russian State University for the Humanities, she worked at Panorama, another think tank, in the mid-1990s before creating Sova together with its current head, Alexander Verkhovsky.
Her regular reports on Russian nationalism made her a target of threats from various radical groups — whose rallies she was not afraid of attending, Panorama head Vladimir Pribylovsky told The Moscow Times on Tuesday.
She never faced actual violence, but had to relocate once to a safe house under police custody, Pribylovsky said.
"She was a good, kind and truly brave person," he said.
Kozhevnikova had admitted in the past to not being fearless, but that did not keep her from doing her job.
"Of course, I'm scared, but I'm used to distinguishing fear and cowardice, and the self-preservation instinct won't make me abandon my favorite job," she said in a 2009 interview after she received e-mailed threats over her work.
Sova will release Kozhevnikova's last report — dealing with ultranationalism in Russia in 2010 — on Thursday, the think tank said on its web site.
Kozhevnikova "departed after a severe illness but continued working until the last moment," her Sova colleagues said in an online obituary.