Ovsyannikova generated headlines in March by appearing on state-funded TV with a placard reading "stop the war, don’t believe the propaganda, they are lying to you here".
Russian authorities have arrested a journalist who famously protested against the Ukraine war on state television.
Marina Ovsyannikova was detained on Wednesday on suspicion of "discrediting" the Russian army, according to her lawyer Dmitry Zakhvatov.
On Thursday, a Moscow court placed her under house arrest for two months.
Osvaynnikova had earlier stated on Facebook that her home was raided by Russian authorities.
"At 06:00, while I was still asleep, ten officers from the Investigative Committee and the police broke into my house," the 43-year-old wrote. "They scared my little daughter. Now they are taking me to the Investigative Committee."
Russian citizens face heavy fines or up to 15 years in prison if they intentionally share "fake news" about Russia's military or its entities abroad.
Ovsyannikova had generated worldwide headlines in March by appearing on the state-funded Channel One with a placard reading "stop the war, don’t believe the propaganda, they are lying to you here."
The latest raid and arrest reportedly relate to a protest that Ovsyannikova staged last month on a river bank with a banner reading "Putin is a killer, his soldiers are fascists".
Ovsyannikova has already been handed three separate fines for her opposition to the war in Ukraine and now likely faces a prison sentence.
After her famous TV protest, she was charged with disparaging the Russian military and fined 30,000 rubles (€256).
She had also been sanctioned for comments in court and on Facebook, where she has supported jailed Russian opposition figure Ilya Yashin and condemned the Russian invasion of Ukraine.
Ovsyannikova has since been seen protesting alone in Moscow near the Kremlin. She has previously labelled the charges as "absurd" and "fabricated".
Ovsyannikova quit as an editor for Russia One after her TV protest and moved abroad to work for the German newspaper "Welt".
She announced in July that she would return to Russia to resolve a custody battle for her two children.
According to Net Freedoms, Russian authorities have launched 79 criminal cases on charges of spreading "fake news" about the military, as well as a further 4,000 administrative cases.