The Rishon Lezion Magistrate's Court on Sunday granted the police's request to extend the remand of Attorney Uri Messer by five days.
Messer, a long-time confidante of former Prime Minister Ehud Olmert, was arrested last week by the Israel Police's National Fraud Unit on suspicion of involvement in the Holyland real estate bribery scandal, which was described by police as the most severe corruption case in Israel's history.
Messer is suspected of serving as an intermediary in the bribery scheme.
In granting the police's request, Judge Avraham Haiman said there was a "direct link" between Messer and the affair, adding that the attorney's conduct during the investigation "speaks for itself."
However, the judge said a distinction must be made between "reasonable suspicion" that warrants the extension of Messer's custody and evidence that can serve as the basis for an indictment.
Police considered releasing Messer to house arrest, but decided against the move in light of new evidence obtained earlier in the day.
During the court hearing, Messer's attorney implied that the request to keep his client in police custody was connected to the fact that Olmert is currently abroad.
The defense attorney said the police's request was based on allegations made by someone who is "untrustworthy."