The interrogation, carried out at the Prime Minister's residence in Jerusalem, lasted five hours, Rosenfeld said.
Netanyahu is suspected of having received benefits from businessmen, according to Attorney General Avichai Mandelblit, who said the investigation relates to crimes of "moral integrity." Netanyahu was also questioned in a second case, but police gave no further details about either criminal investigation into the Prime Minister.
A second suspect was also interrogated in the last two days, Rosenfeld said.
Under Israeli law, only the attorney general can authorize an investigation of the Prime Minister, and Mandelblit said he would release few details about the case so as not to disrupt the investigation.
On Monday night, police investigators spent three hours at the Prime Minister's residence in Jerusalem. It was the first time Netanyahu had been questioned in this corruption probe, officially marking the beginning of the criminal investigation. Netanyahu was questioned "under caution," meaning he is suspected of having committed a crime, and his answers can be used as evidence.
On Thursday night, a police returned to the residence for a second round of interrogation.
Netanyahu has repeatedly denounced the accusations
against him, saying they will all amount to nothing. On Tuesday morning, after the first round of questioning, Netanyahu posted this response on his Facebook page
"Accusation of forbidden election financing - Nothing!
"Accusation of fixing the primary results - Nothing!
"Accusation of receiving benefits abroad and funding flights - Nothing!
"I repeat and say there will not be anything because there is nothing."
This is not the first time Netanyahu has been under criminal investigation. In his first term in office in the late '90s, Netanyahu was the subject of a corruption probe. The investigation did not lead to any charges filed against the Prime Minister, who predicted the same result once again in this latest investigation.
The Ministry of Justice declined to comment, as did Netanyahu's attorney.