The report, written by Ivan Simonovic, U.N. Assistant Secretary-General for Human Rights, alleges the Russian government repressed dissent and anti-Russian sentiment in the days prior to the Mar. 16 election, effectively rigging it in favor of a vote approving Russia's annexation of Crimea.
Russia claimed 97 percent of voters favored the annexation.
“The delegation met with sources who claimed there had been alleged cases of non-Ukrainian citizens participating in the referendum, as well as individuals voting numerous times in different locations,” an excerpt of the report said.
Simonovic did not conclude the results would have been different had the alleged vote irregularities not occurred.
A finalized version of the report will be released during an Apr. 15 presentation to the U.N. Security Council.
Although denounced in the West, the referendum was consistent with international law and thus must be recognized as legitimate, the Russian government has maintained.