A Russian journalist who burst on to a live TV news programme to protest against the war in Ukraine has been reported missing overnight.
Marina Ovsyannikova, an editor at state-controlled Channel 1, was detained after she ran on to the set on Monday holding an anti-war sign.
The sign, clearly visible for a few seconds, read: "No war, stop the war, don't believe the propaganda, they are lying to you here."
Her whereabouts are now unknown.
Ms Ovsyannikova's lawyers say they have been searching for their client but have been unable to find her.
One of them, Anastasia Kostanova, told BBC Russian she had been trying to reach Ms Ovsyannikova by phone but her calls had gone unanswered.
Ms Kostanova said she "spent the whole night looking" for the missing journalist.
"This means that they are hiding her from her lawyers and trying to deprive her of legal assistance and, apparently, they are trying to prepare the most stringent prosecution," Ms Kostanova said.
Another lawyer, Pavel Chikov, posted on Twitter that he was unable find Ms Ovsyannikova.
"Marina Ovsyannikova has not yet been found. She has been imprisoned for more than 12 hours," he said on Tuesday morning.
Her lawyers believe she will be prosecuted under a new criminal law that bans calling Russia's military action in Ukraine an "invasion" or spreading "fake news" about the conflict.
Though the strictest punishments carry a potential prison sentence of up to 15 years, Mr Chikov said Ms Ovsyannikova was likely to be fined 30,000 to 60,000 roubles (£205-£410).
During the protest Ms Ovsyannikova said, "No to war! Stop the war!" before the programme director cut early to a recorded news report. It happened live on Russia's main nightly news programme, Vremya, which is watched by millions.
Before the incident she recorded a video in which she called events in Ukraine a "crime" and said she was ashamed to work for what she called Kremlin propaganda.
"I'm ashamed that I allowed myself to tell lies from the television screen. Ashamed that I allowed Russians to be turned into zombies," she explained. "We just silently watched this inhumane regime."
Ms Ovsyannikova, who said her father was Ukrainian, called on the Russian people to protest against the war, saying that only they could "stop the madness".
"Don't be afraid of anything, they can't imprison all of us," she said.
Ms Ovsyannikova's colleagues at Channel 1 were reportedly surprised by her actions.
One told the Faridaily blog - run by former BBC Russian Service journalist Farida Rustamova - that Ms Ovsyannikova, who has two children, had never discussed politics, but spoke "mostly about children, dogs and the house".
From the moment her identity became known, Ms Ovsyannikova received dozens of comments on her Facebook page in Ukrainian, Russian and English, thanking her for her actions.
Ukraine's President Zelensky also praised her for "telling the truth".
But Kremlin spokesman Dmitry Peskov called her actions an act of "hooliganism".
Russian television news has long been controlled by the Kremlin and independent viewpoints are rare on all the major channels.
State-controlled Russian media refer to the war as a "special military operation" and paint Ukraine as the aggressor, describing Ukraine's elected government as neo-Nazis.
Several of the remaining independent media outlets in Russia have stopped broadcasting or publishing after pressure from the authorities, including the radio station Echo of Moscow, and TV Rain - an online TV channel.
Others, like newspaper Novaya Gazeta, are attempting to report on the situation without falling foul of the new censorship laws.
Access to the BBC has also been restricted inside Russia, leading the corporation to issue guidance over how to continue using its services.
Many social media sites have also been blocked, further restricting the number and diversity of news sources available to people inside Russia.
By Hamzah Abbas, BBC News
A Twitter account that many believed to belong to Ms Ovsyannikova has now been deleted, after it was confirmed to be fake.
The unverified account, which was created this month, quickly gained over 11,000 followers after posting a tweet on Tuesday reading: "I don't know what will happen to me any time soon. My lawyer told me I might be facing time in jail from five to 10 years according to the criminal code. I don't regret it. I need your endorsement though."
But as recently as yesterday, the account was going by the Twitter handle "@JuanArrendondo_" - a misspelling of the name of a US photojournalist who was injured in Kyiv, suggesting the user has gone through various Twitter handles.
The BBC understands that Ms Ovsyannikova is currently in police custody, where it is unlikely she would have access to social media.