Russian police say a masked man broke into the home of the country’s top election official, Ella Pamfilova, and hit her with a stun gun, but she attended a conference unhurt on Friday.
The man broke into her home through a window, just outside Moscow early on Friday, and “repeatedly hit” Ms Pamfilova with the weapon, police said.
Opposition leader Alexei Navalny tweeted that the assault was fake news.
There has been a big police crackdown ahead of local elections on Sunday.
For weeks opposition activists have been protesting in Moscow, angry that Ms Pamfilova’s Central Election Commission barred many independent candidates from standing.
- The students fighting for democracy in Putin’s Russia
- The woman driving Russia’s opposition protests
Hundreds were detained during the protests and some activists were handed jail terms of up to four years.
The demonstrations are the biggest public challenge to President Vladimir Putin’s rule since 2012.
A criminal investigation has been launched into the attack on Ms Pamfilova, 65, which is being treated as attempted burglary. She lives in Istra, a rural district north-west of Moscow.
The intruder did not electrocute Ms Pamfilova with the stun gun and he fled when she brandished a chair at him, a police source told Interfax news agency.
In a tweet, Mr Navalny said it was “a fake attack… intended to distract attention from the [election] falsifications in St Petersburg (there are audio recordings), Moscow and other cities”.
Ms Pamfilova told the Izvestia daily on Friday that she felt well – “everything’s fine, I’m ok”.