Law enforcement officials involved in a probe into suspected corruption by Prime Minister Benjamin Netanyahu reportedly said Thursday that there was “no alternative” to hauling the premier in for questioning.

Anonymous sources with knowledge of the case told Channel 10 that Attorney General Avichai Mandelblit was stalling in upgrading the preliminary probe into a full-fledged criminal investigation.

Details of what the prime minister is being investigated for have not been released.

Get The Times of Israel's Daily Edition by email and never miss our top stories Free Sign Up

The sources argued that even if the case should ultimately be closed, the nature of the evidence requires that Netanyahu be summoned to offer his defense to police on the allegations — going so far as to suggest the prime minister be questioned under caution. Such a move would require the preliminary probe be upgraded to a full-blown investigation, the report said.

“There is no alternative to questioning the prime minister,” an official involved in the probe was quoted as saying.

According to the report, employees in the Prime Minister’s Office were recently called in for questioning by the Lahav 433 anti-corruption unit to explain how gifts allegedly given by donors abroad arrived at the prime minister’s residences.

Earlier this month, Channel 10 reported that Netanyahu’s son Yair will be summoned by police in the near future to give testimony in the investigation. The television report cited “sources in law enforcement” saying that Yair’s testimony was considered relevant to the probe.

In July it was reported that the prime minister may also be called in for questioning, after Mandelblit ordered the preliminary probe into accusations against Netanyahu. The investigation, involves suspicions of massive money laundering, Israeli media reported.

In late July police questioned Ari Harow, a California-born former chief of staff of Netanyahu, under caution, before consigning him to a week of house arrest.

Police are also investigating Netanyahu for financial corruption related to three other matters: longstanding allegations of illicit funding for foreign travel; claims that Netanyahu and his family inappropriately used public state funds for food and entertainment; and the accusation that he illegally received a large sum for political campaigning from French billionaire Arnaud Mimran.

Netanyahu has denied any wrongdoing in all three affairs. His office said earlier this month the latest probe would yield nothing because nothing illicit had been done.