BEIJING (Reuters) - Some Chinese National Basketball Association (NBA) fans have asked for streaming subscription refunds from exclusive service provider Tencent amid a deepening free speech row, a move that could cause the tech giant financial pain.

Tencent Holdings 0700.HK renewed its exclusive digital partnership with the NBA in July, securing rights to stream U.S. games in China, a market with an estimated 500 million fans.

But the Chinese social media giant behind the ubiquitous app WeChat may now become a corporate casualty of the deepening row sparked by Houston Rockets general manager Daryl Morey, who expressed support for Hong Kong protests in a tweet over the weekend.

That prompted a furore in mainland China, and local sponsors of the games have pulled out.

Tencent halted broadcasting games involving the Rockets over the weekend and later said it would stop broadcasting the entire preseason after NBA commissioner Adam Silver voiced his support for Morey’s “freedom of political expression” on Tuesday.

It said users subscribing to the Rockets games can switch to feeds from other NBA teams or apply for a refund.

Refunds have become a hot topic online with more than 3 million views on Twitter-like Weibo social media platform on Wednesday. Some users claimed they had received automatic refunds ranging from 20 yuan to 264 yuan ($2.80-$37), depending on what packages they subscribe to.

Tencent declined to comment on refunds.

The Houston Rockets became the most popular NBA team in China after drafting Chinese player Yao Ming with the first overall pick in the 2002 draft. He became a star and helped build the NBA’s following in China.

Tencent extended its NBA partnership through 2024-25 season in July, according to an NBA statement. The value of the deal was not disclosed, but Chinese sports news portal Lanxiong Sports reported it was worth about $1.5 billion.

Nearly 500 million people watched last season’s NBA games on Tencent’s video platform, up threefold since the 2014-15 season, Tencent said in July.

Tencent isn’t the only company distancing itself from business dealings with the NBA. Chinese Smartphone maker Vivo, state-run broadcaster CCTV and sportswear maker ANTA Sports Products Ltd (2020.HK) all halted cooperation with the NBA on Monday.