The US Federal Bureau of Investigation questioned the son of Labor MK Binyamin Ben-Eliezer last week in connection with an Israeli investigation into alleged financial improprieties by the former presidential candidate, according to Israeli media reports.

Ofir Ben-Eliezer became a key figure in the investigation after his father told investigators that his son was the source of NIS 2.75 million ($800,000) in cash that investigators found in his safety deposit box in a Jerusalem bank earlier this month. The MK said that he was holding the money until his son was ready to buy a house in Israel, Channel 2 reported at the time news of the investigation broke.

Israeli officials have reportedly asked Ofir to return to Israel for questioning and have also requested that the US allow Israeli investigators to question Ofir in the US if he declines to return.

Binyamin Ben-Eliezer was the Labor party candidate for president before he dropped his bid for the post amid allegations that he may have acquired the funds necessary to purchase his apartment in Jaffa’s upscale Laura complex in exchange for providing Israeli businessman Abraham Nanikashvili with certain unspecified services. The apartment, which Ben-Eliezer bought two years ago, is worth close to NIS 9 million (a little over $2.5 million).

Nanikashvili, who was also questioned by police, acknowledged making a $400,000 loan to Ben-Eliezer in 2011, Channel 2 reported, and denied any wrongdoing.

Ben-Eliezer, who initially denied receiving the money but then confirmed doing so, is still under investigation.

Adiv Sterman contributed to this report.