eBay is suing Amazon for allegedly infiltrating eBay's internal messaging system to poach high-value sellers.
The suit claims that the scheme was "startling in breadth," and coordinated from Amazon's headquarters.
eBay says messages were sent from a broad range of countries, and some were successful.
Amazon is investigating the issue.
eBay filed a lawsuit against Amazon on Wednesday alleging that it is has been illegally poaching high-value sellers by infiltrating eBay's internal messaging system, The Wall Street Journal reports.
eBay first accused Amazon of unlawfully poaching its sellers in early October. At the time, Amazon said it was investigating the allegations.
"For years, and unbeknownst to eBay, Amazon has been engaged in a systematic, coordinated effort to infiltrate and exploit eBay’s proprietary M2M system on eBay’s platform to lure top eBay sellers to Amazon," the Journal reports eBay alleges in the suit.
M2M is the company's member-to-member contact system, which allows sellers to communicate with each other, eBay, and customers.
"The scheme is startling in breadth — involving large numbers of Amazon representatives ("Amazon reps"), targeting many hundreds of eBay sellers, and spanning several countries overseas and many states in the United States (including California)."
eBay also claims that Amazon coordinated the effort from its headquarters, citing the fact that many of the messages sent were similar or even identical to each other, and that many accounts used to send the messages were attached to devices linked to Amazon internet protocol addresses, the Journal reports.
eBay alleges that three accounts created by a single individual sent 120 messages to sellers, and that Amazon representatives admitted they were breaking eBay's rules.
eBay also says some of the Amazon representatives were successful in poaching sellers, openly discussing their exploits with those they were targetting.
Business Insider has contacted Amazon and eBay for comment. Amazon told the Journal that it is carrying out a thorough investigation of the accusations.