Tel Aviv: Benjamin Netanyahu's legal woes have deepened after one of his closest confidants agreed to testify against him in a growing corruption scandal, complicating the Israeli leader's efforts to hold on to his job.

Shlomo Filber, the suspended Communications Ministry director and former chief of Mr Netanyahu's bureau, signed an agreement to become a state witness. He turned on his former boss less than a week after police recommended pressing charges against Mr Netanyahu in two other influence-peddling cases – and a day after news broke that police were investigating whether another long-time Netanyahu associate sought to bribe a judge.

Israeli Prime Minister Benjamin Netanyahu speaks during the Conference of Presidents of Major American Jewish Organisations in Jerusalem. Credit:SEBASTIAN SCHEINER

Mr Filber's state-witness agreement could represent a major break in the investigation. Former prime minister Ehud Olmert went to jail for bribery in 2016 after his former secretary turned against him.

"Filber is a close confidant of the Prime Minister who can fully connect all the dots of all the people," said Keevoon Global Research head Mitchell Barak, who served as an aide to Mr Netanyahu more than 20 years ago.