FEMEN feminist group’s co-founder Oksana Shachko, known for winding up world leaders and her topless protests, has allegedly committed suicide.

The 31-year-old from Ukraine was found dead in her Paris apartment on Monday with a suicide note next to her body.

Ms Shachko belonged to the feminist group Femen which regularly challenged the policies of powerful groups and individuals, including Russian President Vladimir Putin.

Unknown assailants are said to have once abducted her while Mr Putin was visiting Ms Shachko’s home country.

Ms Shachko later escaped to France and she was found dead earlier this week, according to activists from Femen.

“It is with great regret and deep pain that I must confirm the death of Oksana,” said Inna Shevchenko, one of Femen’s leaders, who also lives in Paris.

According to local reports, her friends say this was her third suicide attempt in the past two years.

Another Femen co-founder, Anna Hutsol posted on Femen website saying: “RIP. The most fearless and vulnerable Oksana Shachko has left us.

“We mourn together with her relatives and friends,” she said, adding that the group was awaiting “the official version from the police”.

Fellow Femen member Lisa Vinogradova told news agency Central European News: “We are shocked and waiting for the autopsy results.”

While her close friend Valeriy Puzik also took to Facebook: “I have known you since you were 16 and I never could imagine that you would take your own life … You were from another planet, a comet that is flying by. I am recalling a handful of memories about you, R.I.P.”

AAP reported that Ms Shachko was one of four feminist activists who founded Femen in Ukraine in 2008. Exiled in France since 2013, she had since left the group and was working as an artist.

Operating under the slogan “I came, I stripped, I won,” Femen quickly drew attention around the world with its bare-breasted protests against sexism.

Their protests eventually started targeting authoritarianism and racism, with Mr Putin a particular target, alongside France’s far-right National Front party.

But in recent years the group has struggled with internal divisions as well as legal proceedings against its members.

AAP reported that in 2011, Femen said Ms Shachko was among three members “kidnapped” by security agents and forced to strip naked in a forest after staging a topless protest mocking Belarusian strongman Alexander Lukashenko.

The agents had poured oil over the three women, threatened to set them on fire, and cut off their hair, Femen said.

She was abducted again by unknown assailants during a visit by Putin to Ukraine, according to the group.

The Sun reported that there was no immediate comment from Paris police or prosecutors about her death and a post mortem was being carried out on her body to confirm the cause of death.

• If you or someone you know needs help, please contact Lifeline on 13 11 14. For help with depression, please see Beyond Blue for a list of organisations that can assist.