Mexico's peso plunged to its lowest-ever levels on Tuesday night as U.S. Republican Donald Trump led in the key battleground state of Florida and had an edge in a clutch of other states, driving investors to contemplate that Trump could likely be the next U.S. president, Reuters reported.

Concerns of a Trump victory weighed heavily on the peso for months on his threats to rip up a free trade agreement with Mexico and tax money sent home by migrants to pay for building a wall on the southern U.S. border.

The peso weakened by more than 13 percent in Tuesday after-market trading for Mexico and in Wednesday trading in Asia, breaking past 20 pesos per dollar - its biggest intraday fall in at least 19 years.

"There's a lot of panic in the market, it is definitely an outcome it was not expecting," said Juan Carlos Alderete, a strategist at Banorte-IXE. "The movements are very strong, the market is showing higher risk aversion in search of safe-haven assets."

A Trump-inspired peso tumble could push Mexico's central bank to raise interest rates or directly intervene in forex markets to stem the bleed, Reuters said.