Labor Party MK Binyamin Ben- Eliezer was questioned for the fourth time on Wednesday, just two days after details of the allegations against him were cleared for publication.
According to a report on Monday in the Calcalist financial newspaper, Ben-Eliezer is suspected of having accepted $400,000 from oil magnate Avraham Nanikashvili in return for submitting a deposition on his behalf in a 2007 tax probe.
That alleged payment is one of several Ben-Eliezer is suspected of having taken in recent years – payments that totaled in the millions of shekels.
Over the weekend it was reported that his son, Ofir, underwent questioning by law enforcement authorities in the United States, where he lives.
Police here said they had no intention of seeking to extradite him to Israel for questioning as he had not been charged with a crime.
During previous questioning, Ben- Eliezer said that the approximately NIS 2 million in cash he kept in a safe deposit box at a Jerusalem bank was money Ofir had sent him from the US.
The allegations against the MK first emerged just days before the presidential election, in which he was a candidate, leading him to call off his campaign.