Russian-Jewish media mogul Vladimir Gusinsky has been questioned by Israeli police as part of a probe into money laundering allegations.
Mr Gusinsky has twice avoided extradition to Russia
The investigation has already seen the arrest of 25 staff at Hapoalim, Israel's biggest commercial bank.
Mr Gusinsky, whose TV stations had been critical of Russian President Vladimir Putin, fled to Israel in 2000 after being accused of fraud.
Israeli police have frozen $375m as part of the investigation.
They suspect staff at Hapoalim's Tel Aviv branch of laundering assets by shifting money rapidly in and out of accounts, and by awarding loans in exchange for deposits of dirty money.
As many as 45 bank clients are on the police's list of people they want to interview.
Mr Gusinsky was out of Israel when the investigation first went public on 6 March, and was questioned as soon as he returned, police said.
Offices of his businesses in Israel - among other investments, he owns 27% of the firm which runs the daily newspaper Ma'ariv - have been searched.
He has not been arrested and volunteered to be interviewed, his spokesmen say, although Russian media reports say that he has surrendered his passport.
Mr Gusinsky is wanted on money laundering charges in Russia, but has twice escaped extradition - from Spain and Greece - when courts ruled the charges were politically motivated.
Israel has long been a popular destination for Russian money, not least because Israeli law grants citizenship to anyone of Jewish descent.
Many of Russia's richest men are Jewish, and several have been forced to flee the country in recent years after getting on the wrong side of the Kremlin.
Experts say it is unsurprising that a money laundering investigation might therefore be keen to see whether there was a Russian connection.
Israel has had a chequered reputation in dealing with dirty money, and till 2002 was on an international blacklist of money laundering havens.
Its name was taken off after it set up a financial intelligence unit and passed new anti-money laundering laws.