The tapes were in a warehouse full of Michael Jackson's belongings that went up for auction after Joe Jackson failed to pay a storage bill.
Mann says most of them were performances from a variety series the Jacksons did for CBS in 1975.
And he says that the Jacksons were between record contracts at the time, which means they're his and he can do whatever he wants with them.
But an attorney for Michael's estate says those songs are Michael's intellectual property, and thus they belong to the estate. He plans to sue Mann if he releases them.