Updated

A close ally of Prime Minister Benjamin Netanyahu has resigned as coalition whip, robbing the embattled Israeli leader of a key ally as the two men face separate corruption investigations.

David Bitan said Wednesday "the situation" is making it difficult for him to serve as chairman, though he will remain a member of parliament.

Police have been questioning Bitan in relation to accusations he promoted the interests of criminals in return for debt relief while he was a municipal politician.

Bitan, who has denied the allegations, has been the driving force behind a legislation drive seen as aiding Netanyahu.

Netanyahu has been questioned in two cases involving possible bribery, fraud and breach of trust. Netanyahu denies any wrongdoing.