Siobhan O'Connor, Malone's former executive assistant, will speak to 60 Minutes this Sunday night at 7 p.m.
60 Minutes will reveal what the documents she copied show.
According to CBSNEWS.com, O'Connor accuses him of withholding the names of dozens of priests with sex abuse accusations against them from a report released last March.
"Hundreds of documents O'Connor secretly copied from the confidential files of the Diocese of Buffalo offer an extraordinary window into Bishop Malone's decisions about priests accused of abuse. The devout O'Connor professes love for her church and her bishop. But she says she left the diocese last summer after three years because the documents she discovered indicated the bishop had allowed the accused priests to continue in ministry. "The reality of what I saw left me with no other option because at the end of my life, I'm not going to answer to Bishop Malone, I am going to answer to God," she tells Whitaker."