The Israel Police will reportedly question US billionaire Sheldon Adelson and his wife next week as part of an ongoing corruption investigation into Prime Minister Benjamin Netanyahu.

Adelson and his wife Miriam, who are considered close friends of Netanyahu, agreed to speak to police after being told they were not suspects in the corruption investigation, the TV report said.

In leaked audio recordings from 2014, Netanyahu appeared to promise to advance legislation designed to hobble Adelson’s free Israel Hayom daily newspaper in exchange for more favorable coverage from the competing paper Yedioth Ahronoth.

According to Channel 2, Israeli investigators are expected to ask Sheldon Adelson whether he was aware of the alleged quid pro quo deal the prime minister is heard discussing with Yedioth publisher Arnon Mozes in the recordings. Netanyahu denies any wrongdoing in the case, known as “Case 2000,” and legislation to curtail the free daily was not advanced.

US billionaire businessman Sheldon Adelson (L) meets with Benjamin Netanyahu during a ceremony at the Congress Hall in Jerusalem, August 12, 2007. (Flash90)

US billionaire businessman Sheldon Adelson (L) meets with Benjamin Netanyahu during a ceremony at the Congress Hall in Jerusalem, August 12, 2007. (Flash90)

Police have wanted to question the Las Vegas casino magnate for some time in connection with the investigation. Investigators reportedly reached out to Adelson prior to his expected visit later this month, which is timed to coincide with US President Donald Trump’s visit to Israel. The Adelsons will reportedly extend their stay for a few days after the US president leaves to be questioned by police.

In the recordings, Netanyahu and Mozes reportedly referred to Adelson as “the gingy [redhead].”

In the other investigation into the prime minister, known as “Case 1000,” police are probing expensive gifts allegedly given to Netanyahu and his family by wealthy businessmen including US-Israeli movie mogul Arnon Milchan and Australian billionaire James Packer, and whether any actions subsequently taken on their behalf amount to graft or conflicts of interest. The gifts were reportedly valued at hundreds of thousands of dollars and included expensive cigars, champagne, meals and hotel rooms.

Netanyahu has repeatedly denied any wrongdoing in the cases, insisting that “there will be nothing because there was nothing.”