The Israel Police's National Fraud Squad will conduct a criminal probe into allegations that Labor Party activists engaged in election fraud during the party's May primaries, police announced Thursday. This is the third consecutive Labor primary in which police have become involved. It followed an internal Labor probe that determined that "unkosher and illegal activities" took place, and that there were suspicions of forgeries. According to the investigation, in the polling stations in question people were caught voting twice, a man voted dressed as a woman and hundreds of votes were recorded where only a few dozen people had voted. Police Intelligence and Investigations chief Cmdr. Yochanan Danino confirmed that he had been approached by former judge Amnon Straschnov, chair of the party's elections committee, who said there were suspicions of election fraud. Danino then ordered a preliminary probe to determine whether there was adequate grounds to justify a criminal probe. Sources close to the investigation said that in recent days, Danino received information that strengthened the suspicions of campaign fraud, particularly at polling sites in Arab communities. The allegations concern four polling sites during the second round of the primaries. MK Ami Ayalon emerged as the victor at two of the suspicious sites, and Labor Chairman Ehud Barak won at the two others. "We hope the investigation will be quick and we are ready to cooperate in any way required," Labor Party spokesman Lior Rothbart said. But a source close to the investigation said police were examining the voting in the Arab and Druse sectors on a much wider scale. Labor activist Dani Cohen, who worked as a strategist for Ayalon in the campaign, said he was not surprised by the investigation and that he hoped police would succeed in finding the truth. Sources close to Ayalon said the probe would "cloud Barak's victory and hopefully force another primary." Barak declined to comment. Labor MK Ophir Paz-Pines, who also ran in the race, called the investigation "very unfortunate but unavoidable." "There was corruption in the race and it's unfortunate that the party's committees didn't do enough to stop it," he said.