Prosor wrote to U.N. Secretary-General Ban Ki-moon protesting a May 3 incident in which Ann Dismorr, director of the U.N. Relief and Works Agency in Lebanon, held up a map of Israel labeled "Arab Palestine," The Jerusalem Post reported Thursday.
The Palestinian state was surrounded by the modern-day borders of Egypt, Jordan, Syria and Lebanon, the newspaper said.
"Israel supports UNRWA's important humanitarian work; however, actions that encourage incitement, conflict and, ultimately, violence undermine this work," Prosor wrote in a letter to the secretary-general.
UNRWA spokesman Chris Gunness denied the allegations.
"The map in question is an embroidery depicting a pre-1948 map and therefore antedates the creation of the state of Israel," he said.
Prosor however noted the map wasn't just labeled "Palestine" but was presented under the banner of the Palestine Liberation Organization flag.
"It's quite something for UNRWA to insist that the map predates the creation of Israel, given that the PLO only adopted this flag in 1964," Prosor said.