According to the FCRA and FCDPA, Once a Collector no longer has authority of an account, it must be deleted regardless to whether the account was returned to the original creditor or sold.
However this is rarely done and sometimes charges off are listed several times from different collectors.
When disputing make sure you NEVER dispute the account as being Paid e.g. “I Paid this account” remember Paid collections are calculated the same as an unpaid for credit scores.