Mainland e-commerce portal Alibaba.com has accused Yahoo! China of downloading the contact details of 50,000 clients and other sensitive information from one of its websites.
Alibaba's online auction unit, Taobao.com, said its legal counsel had sent Yahoo! a letter warning the latter not to use the information and demanding the 121 gigabytes of data be destroyed.
'We welcome competition but we do not wish to see malicious competition through unfair collection of competitive information,' Taobao said.
Yahoo! regional marketing manager Pauline Wong said the United States internet giant had not received the letter and would not respond directly to the accusations. 'It's our policy not to comment on competitors,' she said.
Taobao's charges come amid intensifying competition in China's consumer-to-consumer auction sector. EachNet, which internet auction giant eBay took over last year, commands an estimated 90 per cent of the market.
Alibaba established Taobao last year, while Yahoo! has joined forces with mainland portal Sina.com on auction services. Taobao suggested Yahoo! downloaded the information to jump-start its auction services. Users visiting Taobao's site between April 9 and 13 complained they were having trouble accessing the company's web pages, with glitches occurring at about 2pm every day.