Lieberman suggests Israeli PM Netanyahu sent investigators to spy on him
The leader of the Yisrael Beitenu party said Netanyahu "isn't capable of understanding concepts like friendship or loyalty", Haaretz reported.
In his comments to the Israeli Maariv daily, Lieberman also said he wouldn't be shocked in Netanyahu had him and his family followed by private investigators.
"The problem with Bibi is once you have a different approach or perception than his, and it goes against his interests, you immediately become a personal enemy," Lieberman said.
"You are immediately accused of hating the prime minister, that you're a leftist and that you're trying to overthrow him, while ignoring the facts."
According to Haaretz, Lieberman also called Culture Minister Miri Regev "a beast" and Foreign Minister Yisrael Katz a "pathetic liar".
Netanyahu, nicknamed Bibi, met Lieberman on Thursday morning to discuss as Israeli politics remain deadlocked after a September election that indicated no clear majority.
Lieberman's nationalist Yisrael Beitenu party, which won eight seats, could end up playing a kingmaker role in efforts to form a government.
Lieberman has declined to endorse either Netanyahu or hsi rival Benny Gantz for now.
When asked about a rotation agreement for the prime minister position, Lieberman said: "They can go to hell. I care about essential issues."
Lieberman has insisted on a unity government between his party, Netanyahu's right-wing Likud and Gantz's centrist Blue and White.
He said he could not for now back Netanyahu because he is willing to form a coalition with Israel's ultra-Orthodox Jewish parties, which he accuses of seeking to impose religious law on the secular population.
Comment: Palestinian hopes don't lie in Israel's election, but in America 2020
Lieberman also said he could not back Gantz for now because he may reach a deal with either the ultra-Orthodox or Israel's Arab parties, which he called "enemies."
Lieberman's dispute with Netanyahu over the ultra-Orthodox Jewish parties caused negotiations to break down after April elections, triggering fresh polls.
Soviet-born Lieberman served as Israel's Defense Minister from 2016 to 2018, when he resigned because of a ceasefire in Gaza which he described as "surrendering to terror".