The New Zealand Rugby Union (NZRU) has backed adidas over the All Blacks' replica jersey, saying the sporting goods giant should not reduce its wholesale price.

Major sports stores yesterday slashed the price of two replica jerseys, after failing to persuade adidas to drop its wholesale price in the face of widespread criticism from sports fans, former All Blacks and politicians.

NZRU chief executive Steve Tew today said adidas were right not to drop the wholesale price.

"Not once they put it in the market, they've got a pricing strategy, it's very comprehensive ... anything they decide in New Zealand has to stick with their strategy in other markets and it's not as simple as looking at one pocket problem and dealing with it in isolation," he told Radio Sport.

"They've got to consider at wider range of issues and in the end we've said to them 'we don't expect you to tell us how to play test matches, we'll keep an eye on how things are going with our brand but ultimately the distribution and sale of our product in New Zealand is your expertise and we'll let you do it'."

Adidas was "in a very difficult position" as it could not openly criticise its retailers or release commercially sensitive information, Mr Tew said.

Meanwhile, sales of the replica jerseys have leapt following the price cut.

Rebel Sport owner Rod Duke today said there had been a noticeable increase in sales.

"They've gone particularly well, we announced it (the price drop) at 11 o'clock yesterday and through all Rebel Sport stores trading is very brisk."

The retailer knocked $50 off the price of the rugby World Cup replica All Blacks jersey, taking it to $170, while the standard All Blacks replica jersey was $30 cheaper at $149.50.

The row was sparked after the two shirts were listed on the website at US$89.99 ($110) and US$79.99 ($97.85) respectively, plus shipping.

Stirling Sports and Champions of the World matched the price cut, but Champions of the World managing director Gary Marshall said they would not be making a profit on the jerseys.

Mr Duke yesterday said he was upset adidas had refused to reduce its price.

"We happen to believe that this jersey belongs to the New Zealand public," he said.

"They don't own it. We all do. We cannot have a situation where New Zealanders would pay more for All Black jerseys than almost any other country in the world."