Police are scheduled to question Prime Minister Ehud Olmert under caution this morning, with the focus of the interrogation being the potentially incriminating testimony given by his long-time friend and former partner, attorney Uri Messer. Police believe that today's session could prove "decisive" in establishing the premier's guilt or innocence.

Olmert is suspected of having received large sums of money over the course of several years from American fund-raiser Morris (Moshe) Talansky. Police believe that Messer served as Olmert's "banker," storing the money the premier received from Talansky in a safe in his office.

According to sources involved in the investigation, Messer gave the police both documents and oral testimony that strengthen their suspicions that most of the money Olmert received from Talansky did not, as the premier has claimed, go to covering debts incurred during his election campaigns for mayor of Jerusalem, but was rather earmarked for his personal use.

This is the second time in two weeks that Fraud Squad investigators have questioned the premier. However, much new evidence has accumulated since Olmert's last interrogation, including Messer's testimony. Messer was questioned again for several hours yesterday, in part as preparation for Olmert's questioning today.

At today's session, interrogators are expected to confront Olmert with additional testimony obtained from Talansky over the last few days.

In addition, they will press him on a weak spot in his previous testimony. At that time, he told the police that his former bureau chief, Shula Zaken, could give them a full explanation of the financial transactions between himself and Talansky, since she kept minutes of all his meetings with Talansky and recorded all the fund transfers. But Zaken has steadfastly refused to talk, meaning that whatever exculpatory details Olmert thought she might provide remain unknown to the police.

Today's interrogation is only expected to last for about an hour - a relatively short time for a case of this nature. However, it seems likely that Olmert will be questioned a third time once police have finished taking testimony from other witnesses.

The reason Olmert is being interrogated today, despite the fact that other witnesses remain to be questioned, is because police want to "lock him in" to his story before Talansky's scheduled deposition to the Jerusalem District Court on Sunday. By law, Olmert's lawyers must be given all the evidence gathered to date before the deposition, so that they can effectively cross-examine Talansky during the hearing. But police fear that seeing this material - and hearing Talansky's testimony, which will be given in open court - will enable Olmert to tailor his story to what they already know while concealing what they do not know. For this reason, they prefer to get his version before he sees the material.

However, it is not yet certain that Talansky will testify on Sunday, since at 9 A.M. this morning - an hour before the police question Olmert - the Jerusalem District Court will hear a request by Olmert's attorneys to delay the deposition by two weeks, in order to give them more time to study the material. Over the last two days, prosecutors have given Olmert's lawyers 22 binders full of material - and that does not include either Messer's testimony or the latest testimony by Talansky, which will be handed over only following the premier's interrogation this morning.

An injunction barring Talansky from leaving the country expires at 11 P.M. this coming Monday, and Talansky wants to return to the United States immediately thereafter. He has said that he would be willing to return to Israel.