The images have gone viral and show one sign that reads: "To our Jewish guests. Please take a shower before you go swimming and although after swimming.
See also: Hotels will stop using keycards soon
See also: This is the best hotel in the world
"If you break the rules, I'm forced to close the swimming pool for you."
The owner of the apartment house, Ruth Thomann, has dismissed claims of anti-semitism and said: "I used the wrong words."
She explained her reasoning behind the swimming pool sign, saying: "Some of these guests went swimming with clothes on, with t-shirts, and didn't take a shower.
The Telegraph reported that Israel has launched a formal complaint with the Swiss Foreign Ministry over the signs.
Meanwhile the Israeli deputy foreign minister has been quoted saying: "It is an anti-Semitic act of the worst and ugliest kind."