Police opened an investigation Wednesday into alleged harassment of Attorney General Avichai Mandelblit.
A police statement said the “repeated” harassment occurred in recent days, but did not elaborate further.
“At this stage we cannot go into the details,” the statement said.
According to Hebrew media reports, the harassment constituted threatening text messages sent to the attorney general’s phone.
Five people have been detained for questioning in the probe, Channel 12 news reported.
The network said the messages urged Mandelblit to open an investigation into Blue and White party MK Yair Lapid over a widely criticized campaign video he released portraying ultra-Orthodox lawmakers as venal.
In recent years, Mandelblit has been subject to both right-wing and left-wing criticism over his handling of a series of corruption cases involving Prime Minister Benjamin Netanyahu.
In December, the grave of Mandelblit’s father was vandalized, with the tombstone cracked in several places.
Police have investigated the vandalism, but no suspects have been charged so far.
At the time, Channel 13 news reported that Mandelblit’s security detail had been expanded, with officials linking the added protection to police intelligence on possible threats against him. The decision to boost security for Mandelblit was made prior to the gravestone incident, the TV report said.
Mandelblit was first given a bodyguard two years ago, according to the network, due to weekly protests by left-wing demonstrators outside his home calling for him to press charges against Netanyahu.
In February, Mandelblit announced he intends to charge Netanyahu with fraud and breach of trust in three corruption cases, as well as bribery in one them.
A pre-trial hearing is scheduled for early October, after which Mandelblit will announce whether he will indict the premier.
Netanyahu has denied any wrongdoing and claimed the charges are an effort by the media and his political rivals to force him out of office.