Authorities in Serbia's capital are facing outrage over the purchase of a plastic Christmas tree that reportedly cost 83,000 euros ($98,000) and has sparked corruption allegations.

An anti-corruption website has described the 18-meter (59-feet) tree as the most expensive in the world — four times the price of the one outside Rockefeller Center in New York.

Mayor Sinisa Mali says he wasn't aware of the cost and would cancel the deal, but opposition groups have alleged he was involved in corrupt and wasteful use of public funds.

Several dozen opposition supporters rallied Friday by the tree at a Belgrade central square. They held banners reading "Shame on you" or "Bigger than Rockefeller."

A citizen, Misha Zivkovic, says "it is unbelievable how shameless (the authorities) are."