A Russian senator submitted his resignation on Tuesday after a leading opposition anti-corruption crusader accused him of having property abroad and holding Israeli citizenship under a Hebrew name.
Vitaly Malkin, a member of Russia's upper house, the Federation Council, disputed the charge, saying he had renounced his passport in 2007 after a law was passed in 2006 banning state officials from having dual nationality.
"I have not been a citizen of Israel since August 2007," Malkin, 60, said at a specially called meeting at the Federation Council, noting he was stepping down to protect his reputation and that of the chamber.
"I have not closed a door for myself here, I simply decided to renounce my status in order to protect my honest name," he said in a speech whose transcript was released by the Echo of Moscow radio.
He resigned after Alexei Navalny, arguably the most charismatic leader of Russia's opposition movement, posted documents online showing Malkin had Israeli citizenship under the Hebrew name Avihur Ben Bar.
Malkin was deputy head of the Federation Council's international affairs committee and as such might have had a special security clearance giving access to classified information, Navalny speculated.
The blogger also accused Malkin of failing to declare business interests and property in Canada.
The Federation Council dismissed Navalny's official inquiry but had to react when mass-circulation tabloid Moskovsky Komsomolets sent its own request to the chamber.
Malkin accused media of organising a coordinated campaign against him and claimed that his ouster was also the result of his involvement in the so-called Magnitsky affair.
With an eye to putting together a file on the Magnitsky case, the senator visited US Congress last summer, months before US authorities passed the so-called Magnitsky Act which blacklists Russian officials implicated in the prison death of lawyer Sergei Magnitsky.
Magnitsky, who worked for Western investment fund Hermitage Capital Management, died in prison from untreated illnesses in 2009 after he claimed to have discovered a major tax fraud covered up by government officials.
Malkin on Tuesday accused Hermitage Capital of being involved in the campaign to discredit him.
"I have become a convenient figure for them, and they organised this campaign to persecute me," Malkin told fellow senators.
Head of Hermitage Capital Bill Browder denied the claim.
"We had nothing to do with any campaign related to Vitaly Malkin," he said in an emailed statement.
Malkin's resignation is another feather in the cap for Navalny, Russia's top opposition blogger whose earlier expose forced a leading lawmaker to resign last month.
Vladimir Pekhtin, the head of the ethics committee at parliament's lower house, the State Duma, quit after Navalny and his associates posted property deeds and other documents online showing the lawmaker had US-based property worth over $2 million.
But other lawmakers remain unperturbed by the exposes by opposition activists and media.
A report by the opposition magazine The New Times that Irina Yarovaya, a senior member of the ruling United Russia party, lives in a Moscow apartment worth nearly $3 million went largely unnoticed.
The opposition charges that the State Duma lacks legitimacy because 2011 parliamentary elections were slanted in favour of United Russia.
The parliament has been tainted by so many corruption allegations and other scandals that some critics have called for the lower house to be disbanded.