An associate of the mayor of Beit Shemesh was arrested last week and remains in police custody over suspicions of involvement in voter fraud in last month’s contested municipal elections.

Police also questioned eight others, including the son of United Torah Judaism MK Meir Porush, but released them after questioning.

A gag order on the case was lifted late Sunday.

The police’s Lahav 443 special investigations unit began an examination of the allegations after police found 160 identity cards in an apartment and in a car in the city.

Investigators suspect that Shaya Brand, an associate of Mayor Moshe Abutbul, organized a plan to identify nonvoters and pay them for their identity cards, so that Abutbul supporters could use them to cast fraudulent votes, police spokesperson Micky Rosenfeld said.

Abutbul won the election over challenger Eli Cohen by less than 1,000 votes.

Last Tuesday, 2,000 Beit Shemesh residents protested outside of city hall, calling for the nullification of the election results due to the voting irregularities.

Beit Shemesh, a city of 75,000 in the Judean mountains outside Jerusalem, has become deeply divided in recent years as neighborhoods have seen a large influx of ultra-Orthodox residents.

The city has been the scene of sometimes violent tensions between the Haredi population and other residents. In 2011, eight-year-old Naama Margolese was spat on and insulted by Haredi men when walking to her school, at the edge of an ultra-Orthodox neighborhood, bringing national and international attention to the city.

In July 2012, Egged was ordered to compensate a young girl who was forced by ultra-Orthodox passengers to sit at the back of a bus in the city. The presiding judge ruled that gender segregation on a public bus was illegal and it was the driver’s responsibility to prevent it.

In July of this year, a group of Haredi men reportedly smashed the windows of a bus after a woman refused to give up her seat and sit in the back. Haredi rioters have also violently protested construction at a Beit Shemesh site that once may have been a burial ground.