EBay (EBAY) says Amazon employees used the auction site’s messaging service to contact top sellers in hopes of convincing them to switch platforms. EBay’s internal investigation uncovered recruiting activity spanning several years and multiple continents.

EBay is now accusing Amazon (AMZN) of intentional interference with contractual relations and economic relations, as well as fraud and violation of California penal and business and professions codes, the Wall Street Journal reports.

Three accounts created by one person sent more than 120 messages to sellers without conducting any actual business on the platform, eBay alleges. The Amazon employees acknowledged they were breaking eBay’s rules and actively tried to avoid detection, the lawsuit says.

In the complaint, filed in Santa Clara County in California, EBay asks the court to permanently prohibit Amazon from misusing its messaging system and for unspecified monetary damages to be determined in a jury trial. An Amazon spokeswoman told the WSJ the company was conducting a thorough investigation of the accusations.

EBay and Amazon both rely on the independent merchants who sell on their platforms. Amazon has more customers and sales than EBay, but some sellers still prefer EBay because EBay doesn’t compete with its merchants for sales like Amazon does. EBay also lets merchants communicate directly with customers, while Amazon discourages merchants from communicating directly with Amazon shoppers.

Neither company discloses how many sellers use their platforms, but gross merchandise volume in 2017 was $88 billion for EBay and $186 billion for Amazon. More than half of Amazon’s overall sales are via third-party sellers.