Occupied Jerusalem: Israeli Prime Minister Ehud Olmert underwent a fifth police interrogation on Friday for bribery and fraud allegations, a police spokesman said.

Police are investigating allegations that Olmert took bribes from a US businessman and made double claims for travel expenses while in politics. Olmert has denied wrongdoing.

The prime minister was questioned at his official residence in Occupied Jerusalem for three hours, the spokesman said.

Olmert announced last week he will not run in his ruling Kadima party's internal elections on September 17 and will step down after a successor is chosen.

Four Kadima ministers have launched campaigns to replace Olmert, with Foreign Minister Tzipi Livni leading the pack and Transport Minister Shaul Mofaz, a former defence chief, close behind her.