Counterfeiters have already started churning out fake versions of Canada's new $100 polymer bills, but police say it's easy to spot the difference in the transparent strip.

New Westminster police say two fake hologram $100 bills have already been found at a local business and a major bank.

But Sgt. Diana McDaniel said the difference between the real thing and the counterfeit bills is clear.

A real bill clearly shows the flag and rooftop of Parliament Hill's Peace Tower in the hologram window, along with the number 100, repeated several times.

"But on the counterfeit $100 bills, the 100, the rooftop and flag are clearly not present," said Sgt. McDaniel.

Investigators are still trying to find the source of the bogus bills.

The new $100 bill was introduced in November 2010, the first in a series of "secure" polymer banknotes introduced by the Bank of Canada, largely to thwart counterfeiters.

New $50 and $20 bills are also in circulation, with $5 and $10 coming in November.