NEW YORK - Ice cream thieves are on the rampage in New York and one billionaire has reached melting point. The supermarket tycoon Friday offered a $5,000 reward leading to their arrests and prosecution.

John Catsimatidis, who owns the Gristedes chain of grocery stores, told AFP he was fed up with a ruthless gang cleaning out his freezer cases and selling luxurious cartons to corner stores for a fraction of the price.

"It's a nice summer reward," he said. "Our managers have been going through the refrigerator cases and they're wiped out.

"This gang of three to four people comes in and puts them in large shopping bags, they distract the manager and sell them," he added.

The biggest single theft was around 100 to 125 tubs worth $700-800, with stores in Manhattan the hardest hit, he said.

The scam had been going on six months, Catsimatidis complained.

The reward comes with New York in the grip of a heatwave, expected to last through Sunday.

With the humidity, it could feel as hot as 110 degrees Fahrenheit (43 degrees Celsius) although real temperatures will be lower.

Asked whether he thought his $5,000 reward would have an impact, the self-made tycoon replied that maybe the corner store owner buying the ice cream would turn in the thieves.

"We've got to get this gang!" Catsimatidis said.

The billionaire announced the reward on Twitter, saying "ice cream bandits are wreaking havoc on NYC supermarkets" -- quoting a headline in the New York Post tabloid.

Police confirmed 250 complaints of ice cream theft and 130 arrests so far in 2016.

"We are working closely with the retailers to combat the thefts of ice cream," a spokesman told AFP.

Catsimatidis, who immigrated to New York with his family from Greece as a baby, is valued at $3.4 billion by Forbes.

The 67-year-old philanthropist is also a Republican donor who ran unsuccessfully for mayor of New York in 2013.

Gristedes operates more than 30 stores throughout Manhattan, Brooklyn and suburban Westchester County.