Netanyahu late Saturday lashed out at the police on his Facebook page over leaks to the Israeli media related to the graft investigation.
That prompted a stern response from the police, who have been probing gifts Netanyahu allegedly received from wealthy supporters as well as suspicions he sought a secret deal with the publisher of a top-selling newspaper.
His wife Sara has faced a separate investigation into alleged misuse of public funds.
Netanyahu has repeatedly denied any wrongdoing and has accused members of the Israeli media of seeking to force him out of office.
Israel's Channel 2 television reported Saturday night that the long-serving prime minister is to soon be questioned again by police as part of the investigation, prompting Netanyahu's Facebook post.