A mysterious box of letters, memos and legal documents pertaining to the White Sox team accused of throwing the 1919 World Series -- some of the papers thought to be lost since the middle of the last century -- is bound for the auction block this week after being uncovered by two Chicago-area collectors.

The identity of the sellers is not being disclosed and the story of how the papers came to emerge is incomplete. The auction house, Mastro Auctions in Burr Ridge, says the owners probably bought the box at a file sale without knowing what was inside. The auction house would not go into detail about its origins.