Olmert's legal advisor Amir Dan said that "the publication of investigation material over the past two days is not coincidental. The police are briefing a witness and coordinating versions ahead of Talansky's testimony next week at the Jerusalem District Court."
"The briefing of witnesses through the media by the police must be stopped. They are disrupting investigation procedures," he said, adding that the police's method "will undoubtedly be probed in the future."
During his police interrogation, the prime minister claimed he had received several envelopes containing hundreds of dollars for board and lodging expenses, rather than for personal needs.
Law enforcement officials have said that evidence collected by police investigators in the United States strengthen the suspicions against Olmert.
The prime minister will be questioned by the police Friday morning for the third time since the bribery offenses he is suspected of were made public.
Investigators of the police's National Fraud Investigation Unit will arrive at the prime minister's official residence in Jerusalem and present him with questions regarding the suspicions against him.
Jewish American philanthropist Talansky is expected to return to Israel soon in order to undergo a cross examination next Thursday by Olmert's lawyers, following his pre-trial deposition at the Jerusalem District Court in May.
The prime minister recently estimated in talks with Kadima activists that "this deposition will collapse in the cross examination."
Olmert is suspected of illicitly receiving funds before beginning his tenure as prime minister. According to the suspicions, he received envelopes containing cash money, believed to amount to hundreds of thousands of US dollars, for a long period of time.
Talansky testified for seven hours at the Jerusalem District Court on May 28, and said he had provided the prime minister with cash envelopes and credit cards and paid for his flights and his stays at luxury hotels, in addition to a generous loan of hundreds of thousands of dollars.
A police statement, issued in response, offered the following comment: "We regret this conduct, which is obviously a ploy meant to distract attention from the main issue at hand. The investigation team, headed by Brigadier-General Shlomi Ayalon is performing its duty in a professional manner, away from the limelight, it an attempt to get to the truth."
Roni Sofer contributed to this report