eBay Inc's StubHub online ticket resale service said it was the victim of a massive international cyber fraud ring, the details of which authorities plan to disclose on Wednesday as they announce arrests in the case.

StubHub's head of global communications, Glenn Lehrman, told Reuters late on Tuesday that his firm has been working with law enforcement around the world for the last year on the case.

Lehrman said he could not say how much money was involved or how many people were being charged ahead of announcements planned by authorities in several countries on Wednesday.

Fraudulent charges were posted after hackers obtained user credentials by hacking into other sites, then used them to log in StubHub, he said.

"We did not have anyone who hacked into our system," Lehrman said.

He said the schemes involved a "pretty intense network of cyber fraudsters working in concert with each other."

Manhattan District Attorney Cyrus Vance will announce details about the arrests along with the Royal Canadian Mounted Police, the City of London Police and the U.S. Secret Service, according to a release from Vance's office on Tuesday.

A spokeswoman for the District Attorney's office declined to elaborate.