A year after opposition activist Anastasia Shevchenko was placed under house arrest, she has discovered a spy-camera was installed in her bedroom and secretly filmed everything for months.
Investigators showed her the footage.
It includes images in her underwear, gathered as they sought incriminating evidence of political activism.
Her family, who also had their conversations tapped, have described their upset at what they call a "very low move" by the authorities.
Ms Shevchenko, 40, is herself banned from communicating with the outside world from the flat in the southern city of Rostov on Don.
The activist's teenage daughter, Vlada, says her mother discovered from investigators last autumn that they had bugged the family flat, when they presented her with page upon page of annotated transcripts.
"Then, last month, investigators showed her photographs and she realised they'd been filming her too," Vlada wrote to the BBC.
"From the pictures we realised they'd installed the camera opposite Mum's bed, on the air conditioning unit."
Vlada, who keeps a blog of her family's experience, wrote on Facebook that the revelation was "humiliating, yes. For the men in epaulettes", a reference to security services.
But Ms Shevchenko's mother, who lives with Anastasia and her two children, admitted that they had been disturbed by the revelation.
"There were pictures of her in just her bra; the children were on the footage too. It's really unpleasant," Tamara Gryaznova told the BBC.
"There were video and audio recordings; all our conversations. Now the investigators are making her go through it all to confirm it's authentic. We never expected that they'd stoop so low."
Spy-cam operation 'pointless'
The family's lawyer, Sergei Badamshin, has confirmed that the equipment was secretly installed in the family home in autumn 2018, authorised by a local court.
Police also kept Ms Shevchenko under surveillance outside her flat.
She was later charged with membership of an "undesirable organisation", under a 2015 law, for her links to a group founded by Mikhail Khodorkovsky, a former oligarch and now fierce critic of the Kremlin.
Mr Badamshin mocked the results of the five-month operation as "pointless", given that the evidence of his client's activity being a "threat… to national security and the constitutional order" amounted to attending a human rights conference and an authorised street protest.
But it's the intrusion into Ms Shevchenko's most private space that has disturbed her family.
"They could have put the camera over the table," Tamara Gryaznova pointed out. "But they put it over Nastya's bed."