Israeli police will question Prime Minister Ehud Olmert for a second time on Friday, a police spokesman said, as part of a bribery investigation that could force him from office.
Police, who first questioned Olmert on May 2, have said he is suspected of taking "significant sums of money from a foreigner or a number of foreign individuals over an extended period of time".
Olmert has denied any wrongdoing but said he would resign if indicted.
He acknowledged earlier this month that U.S. businessman Morris Talansky raised funds for his two successful campaigns for mayor of Jerusalem in 1993 and 1998, a failed bid to lead the right-wing Likud party in 1999 and a further internal Likud election in 2002.
Israeli law broadly prohibits political donations of more than a hundred dollars.
"Olmert will be questioned for the second time by investigators from the National Fraud Unit this coming Friday," police spokesman Micky Rosenfeld said on Tuesday.
Israel's chief prosecutor said on Monday investigators suspected Olmert had taken envelopes full of cash from Talansky.
Olmert has said his former law partner handled the details, voicing confidence the attorney made sure proper procedures were followed. A judicial source said the sums involved totalled hundreds of thousands of dollars.
On Sunday, Attorney-General Menachem Mazuz said the investigation, one of several focusing on corruption suspicions against Olmert, would not be finished any time soon.