Investigators from the National Fraud Unit continued on Tuesday with intensive preparations to confront former prime minister Ehud Olmert over suspicions he received bribes from businessmen backing the Holyland real estate development in south Jerusalem.In the meantime, two key suspects in the investigation, ex-Bank Hapoalim chairman Dan Dankner and Olmert’s former aide of 30 years, Shula Zaken, were brought to the National Fraud Unit’s headquarters in Lod for questioning.Zaken continued to deny suspicions against her that she acted as the “main pipeline” – as described by a police representative in court during her remand hearing on Monday evening – for bribes destined for Olmert when the latter was Jerusalem mayor and minister of industry, trade and labor. Zaken is also suspected of pocketing a portion of the bribes herself.RELATED:Jerusalem city engineer: Freeze HolylandIt remains unclear how Dankner responded to questions from detectives. They suspect him of paying a million and half shekels in bribes to then-Israel Lands Administration head Yaakov Efrati, to ensure that industrial land he owned in Atlit could be converted into profitable real estate developments – dubbed by police as the “salt deal” since Dankner owned Israel Salt Industries during the time of the alleged transaction.Dankner has denied all suspicions against him. His attorney, Joseph Benkel, told The Jerusalem Post on Tuesday that his client’s stance “remained unchanged” since the denial.While Olmert has not been linked by police to the alleged “salt deal,” he did call for it to be approved while he was minister of industry, trade and labor, and police are likely to investigate whether illegitimate considerations were involved in Olmert’s endorsement. Olmert issued a blanket denial of any bribery offenses in a televised speech broadcast earlier this month.Speculation mounts over Olmert arrestSpeculation mounted that police might arrest Olmert in the coming days,although former National Fraud Unit senior investigator Dep.-Cmdr.(ret.) Boaz Guttman told the Post that this was by no means certain.Only fear that Olmert could subvert the course of the investigationwould justify an arrest, Guttman said, adding that the former primeminister “can’t undermine statements made by other suspects in theinterrogation room.”He said police were restricted in the level of surveillance they couldplace Olmert under, noting that while officers could in theory betapping his phone conversations, calls between Olmert and his attorneyscould not be listened to because Olmert is a defendant in three ongoingtrials.“His position as defendant means phone calls to lawyers can’t be tapped,” Guttman said.“The only way Olmert can disrupt the investigation is by disseminatingcase material to the media after he is exposed to them duringquestioning, which has happened in previous investigations, whenOlmert’s representatives published transcripts of interrogations innewspapers,” Guttman added.“The question is, does he have to be arrested physically? The fact thathe has not yet been arrested means that police do not, at this point,have good cause to do so. He could be questioned under caution, but itis not certain that he will be arrested,” Guttman said.Any potential arrest of Olmert would have to be authorized by State Attorney Moshe Lador, Guttman noted.Meanwhile on Tuesday, police released former Jerusalem deputy mayor Yehoshua Pollack to house arrest. Pollack was arrested last Thursday on suspicion of accepting hundredsof thousands of shekels in bribes and acting as an intermediary onbehalf of bribe-givers in the Holyland affair.Pollack, who also headed the municipality’s planning and constructionportfolio, is suspected of promoting two Holyland plans and ensuringthat they received official approval within planning committees, andcutting tens of millions of shekels in costs for developers.Pollack’s attorney, Hezi Shnelzon, claimed police viewed his client ina different light from the other suspects in the investigation since hewas released “before the end of his remand, following negotiationsbetween ourselves and the police.“I believe that says something,” Shnelzon told the Post.“Pollack answered all questions, and told investigators that he carriedout his work in the interest of the city and the state, and in fullcompliance with the law,” the attorney said.