(Reuters) - Amazon.com ( AMZN ) said on Wednesday it plans to push its cashierless shopping technology into more third-party stores this year, even as it reduces its reliance on the technology in its own.

The online retailer said about 140 stores use the system, known as "Just Walk Out," which allows customers to scan an app to enter a store and leave with their items without paying at a register. Amazon ( AMZN ) will more than double that number this year.

The company refuted a report by tech site The Information this month that the technology relies on human reviewers in India to watch customers as they shop.

"Associates don't watch live video of shoppers to generate receipts - that's taken care of automatically by the computer vision algorithms," Amazon ( AMZN ) said in a release. However, it said human reviewers are necessary to help improve accuracy.

The expansion of Just Walk Out tech to third party stores, such as stadiums and Hudson News locations at airports comes as Amazon ( AMZN ) plans to take the technology out of its own existing Fresh grocery stores.

Instead it will rely on "smart" shopping carts that log users items and charge them when they leave the stores, sending a digital receipt. Amazon ( AMZN ) said Fresh customers spend more when they use the carts than those not using the carts.

Amazon ( AMZN ) has been trying to keep pace with Walmart and others with its Fresh stores, delivery options, and the buyout of Whole Foods in 2017 for more than $13 billion.

Just Walk Out, however, has been plagued by hiccups including customer confusion over how it works, missed items and delays in sending receipts, sometimes taking hours or even days.