Two Israeli students were sent home after one of them exposed his rear at the Majdanek concentration camp, Reshet Bet reported.
The 11th-grade students, residents of northern Israel, were visiting Poland together with a group when the incident occurred over the weekend.
The student was interrogated and released after paying a fine. The second student received a warning.
According to Ha'aretz, the incident is the worst involving Israeli students in Poland in years.
In a statement, Israel's Education Ministry said it sees any behavior which harms the trip's values and standing as "very grave."
"In this case, due to the students' unacceptable and inappropriate behavior, we have taken significant steps against them," the Ministry said. "They were returned to Israel, and the educational institution intends to use appropriate discipline methods."
This is not the first time students from Israel have acted in a shameful way during their trip to Poland. Last year, high school students from another town in northern Israel sprayed graffiti on Auschwitz's Block 25.
In another incident, twelve students from a central kibbutz were sent home after they purchased drugs from a Warsaw merchant they had found using a mobile application.