The Office of the Swiss Attorney General would not reveal details about the nature or number of the complaints or who had lodged them.
On Thursday, the upper house of parliament opted not to axe the agency's funding by 23 to 21 votes, a decision that was warmly welcomed by UNRWA chief Philippe Lazzarini.
Initial research suggested he knew his victims, but investigators were still working on establishing his motive, police said.
An Israeli watchdog said the affected groups had ties to the Popular Front for the Liberation of Palestine.
The blue-and-white hosted Switzerland at the Puskás Akadémia Pancho Aréna in Felcsút due to the ongoing war with Hamas as Israel.
"We want to provide an opportunity for the people of Israel to unite around an event that embodies national pride and a triumph for the Blue and White," the initiative's organizer said.
With Euro hopes hanging by a thread, Israel to wrap up its campaign vs Switzerland, Romania, Andorra
While Basel was a hub of Jewish activity in the past, most recently only one kosher restaurant has survived.
The Catholic Church prohibits non-Catholic professors from teaching “doctrinal” courses such as philosophy, liturgy, scripture, Catholic theology, and fundamental theology, at the university.
The bank failed to include numerous relevant records in its probe, according to details from an independent reviewer's report obtained and published by the Senate Budget Committee.