A former top aide to Israel's prime minister is to testify against him in two corruption cases being investigated by police, local media say.
Ari Harow, who was Benjamin Netanyahu's chief of staff, will turn state's witness under a plea bargain in a probe he is facing himself, reports say.
Mr Netanyahu has been questioned about the cases three times by police under caution.
The prime minister, who is serving his fourth term, denies any wrongdoing.
The BBC's Tom Bateman in Jerusalem says Mr Harow's reported agreement with prosecutors marks a significant development in the corruption investigations, whose twists have received near daily coverage in Israel's media.
One of the cases relates to claims that Mr Netanyahu and his family received gifts from wealthy businessmen.
The other centres around allegations that Mr Netanyahu offered to limit the circulation of a rival free newspaper in return for more favourable coverage from one of the country's most widely-read dailies.
The cases are known colloquially as "1,000" and "2,000" respectively.
Mr Harow agreed to confess to fraud and breach of trust in return for testifying against his former boss, Reuters news agency cited court papers as saying.
Mr Netanyahu has repeatedly described the investigations as a witch-hunt stirred up by political opponents.
"We completely reject the unfounded claims made against the prime minister. The campaign to change the government is under way, but it is destined to fail, for a simple reason: there won't be anything because there was nothing," a post on his Facebook page said.
Mr Harow, a former head of American friends of Likud (Mr Netanyahu's party), was the prime minister's chief of staff from 2009-10, and from 2013-15.