Amazon.com Inc. is investigating suspected data leaks and bribes of its employees as it fights to root out fake reviews and other seller scams from its website.

Employees of Amazon, primarily with the aid of intermediaries, are offering internal data and other confidential information that can give an edge to independent merchants selling their products on the site, according to sellers who have been offered and purchased the data, as well as brokers who provide it and people familiar with internal investigations.

The practice, which violates company policy, is particularly pronounced in China, according to some of these people, because the number of sellers there is skyrocketing. As well, Amazon employees in China have relatively small salaries, which might embolden them to take risks.

In exchange for payments ranging from about $80 to more than $2,000, brokers for Amazon employees in Shenzhen are offering internal sales metrics and reviewers’ email addresses, as well as a service to delete negative reviews and restore banned Amazon accounts, the people said.

Amazon is investigating a number of incidents involving employees, including some in the U.S., suspected of accepting these bribes, according to people familiar with the matter. An internal probe began in May after Eric Broussard, Amazon’s vice president who oversees international marketplaces, was tipped off to the practice in China, people familiar with the matter said. Amazon has since shuffled the roles of key executives in China to try to root out the bribery, one of these people said.