Police suspect that Ofir Sasportas, who is accused of mediating between Dudu Topaz and the attackers of Keshet cable television CEO Avi Nir, supplied cocaine to the entertainer.
Topaz, 62, was questioned on the matter on Wednesday, and police are expected to decide in the coming days whether to add drug use to the list of charges against the former television star.
Meanwhile, Israel Police has told the Tel Aviv District Court it plans to indict Sasportas and Roman Aleyev, who allegedly carried out the attempted attack on entertainment agent Boaz Ben-Zion along with Mohammed Yunis.
The court extended Sasportas and Aleyev's remand by five days.
On Wednesday, police arrested underworld figure Moshe Ohana, brother of crime boss Rafi Ohana, for suspicion of orchestrating the assault on Nir and hiring brothers Yanai and Noam Amawi, who allegedly beat the media executive with clubs near his north Tel Aviv home, causing serious injuries.