The Kremlin has denied any involvement in the incident.
"The Russian government is duty bound to explain what happened to Mr Navalny."
"It remains too early to gauge the potential long-term effects of his severe poisoning."
"We condemn this attack in the strongest terms."
The trial reopens one of modern France's darkest episodes.
The Louise Michel was purchased with proceeds from the sale of Banksy artwork.
The boat rescued 89 people on Thursday.
He urged his followers on social media to attack politicians and journalists, police said.
The word "martyr" on the memorial was crossed out, with "menteur" or "liar" daubed next to it.
