Unsuspecting tourists who thought they were buying cheap Banksy knock-offs have scored the bargain of a lifetime after the elusive street artist revealed the paintings were really his.

Banksy used an anonymous old man to sell several of his original works for US$60 ($63.60) from a stall in New York's Central Park on Sunday.

A Chicago man scores hundreds of thousands of dollars worth of Banksy art for $60 each in New York.

The paintings are actually worth around $42,400 each.

It took hours for the man to make his first sale, no doubt because everyone thought he was selling counterfeits.