A female activist in St Petersburg has been brutally murdered in what friends fear may be the start of a new wave of violence against LGBTQ people.

Yelena Grigoryeva, 41, was found on Sunday in bushes near her home with stab wounds to her back and face and signs of strangulation, the Fontanka news outlet reported.

Law enforcement later detained a 40-year-old man with a history of bad debts and charged him with murder, it said.

The killing comes after a homophobic vigilante group called Saw, in the style of the horror film, posted that it had “prepared very dangerous and cruel gifts” for LGBTQ activists including Ms Grigoryeva. Russian authorities banned the group's site last week.

Vitaly Bespalov, a fellow activist and friend of Ms Grigoryeva whose name was also on the Saw list, said her acquaintances suspected the tragedy was connected to her activism.

“She was always standing up against discrimination against LGBTQ people, violence against LGBTQ people, and now she herself has been murdered,” he said.

Ms Grigoryeva had often been photographed at protests holding signs like, “In Russia there are more than 5 million gay people. Because of backwardness and hatred, they have to live secretly”.