The US Department of Justice has opened an investigation into whether eBay executives broke the law and stole trade secrets while sitting on the board of

The investigation is centered on the activities of eBay executives who managed the Craigslist relationship between 2004 and 2007, a period when eBay morphed from a US$30 million (£19 million) Craigslist investor, with a seat on its board of directors, into a direct competitor in the lucrative online classified advertising market.

Nine incidents being investigated

In a federal grand jury subpoena sent to Craigslist's law firm Perkins Coie on 7 September, investigators asked for documents relating to nine incidents during which eBay executives allegedly asked Craigslist for information that was then used to build out eBay's own classified business. This data includes operational details, information on new cities where Craigslist planned to start operating and financial information on the company, according to the subpoena.

Perkins Coie declined to comment for this story. eBay wouldn't say whether it was aware of the investigation before it was first reported by Reuters on Tuesday, but in an emailed statement, company spokeswoman Amanda Miller said, "We will cooperate in any inquiry related to the disputes between eBay and Craigslist."

An ongoing battle 

The two companies have been slugging it out in civil courts for three years now, but the criminal investigation raises the stakes in this ongoing dispute. "eBay believes that Craigslist's allegations against eBay are without merit. We will continue to vigorously defend ourselves, and we will aggressively pursue our claims against Craigslist," Miller said.

The DoJ declined to comment on the investigation, which is being coordinated by US Attorney Melinda Haag in conjunction with the US Federal Bureau of Investigation's Palo Alto, California office.