The frenzied scavenger hunt for large sums of cash hidden in public has hit New York, with $US2,000 ($A2,100) in envelopes stashed across Central Park and Brooklyn.

The brainchild of a group of wealthy friends in California, it is the first time the treasure hunt comes to New York, having sparked internet-driven chases on the West Coast.

“Our biggest day ever! Houston, Mexico City, NYC today! Be safe, be kind, tweet when you find!” the @HiddenCash handle wrote on twitter kicking off the hunt at 10am local time.

The 20 white business envelopes, $US50 in each, carry a handwritten message on the front: “Twitter @HiddenCash. Tweet photo when u find. We heart NY.”

The money comes from wealthy real estate investor Jason Buzi and a group of anonymous friends, who have given to charity in the past but wanted to do something a bit more fun.

A friend of Buzi’s from San Francisco, who gave his name only as Thierry, spoke to AFP as he hid $US1000 in Central Park before setting out to drop another $US1000 in Brooklyn.

“Jason was thinking about doing something a little bit different, more fun – maybe smaller quantities that won’t change anyone’s life, or maybe it will in a different way, depends what they do with it” Thierry said.

“It’s actually encouraging people who find the money and don’t have a particular need… to pay forward and help someone in need,” he added, his face hidden by dark sunglasses and a jet-black beard.

Thierry hides the envelopes and then takes a picture on his mobile phone of the general area, clues that are posted on twitter to drive the hunt.

“Look around the Pond! (59th and 5th). Many there. If you can make it within an hour, it’s not too late! Go!” @HiddenCash tweeted with a picture of a rock.

Retweeted 80 times in minutes, the pond in Central Park soon echoed with cries of adults and children hunting under benches and weaving between tourists to find the cash.