We compute the mutual information of two Hawking particles emitted consecutively by an evaporating black hole. Following Page, we find that the mutual information is of order exp(-S) where S is the entropy of the black hole. We speculate on implications for black hole unitarity, in particular on a possible failure of locality at large distances.
Izuka, Norihiro and Kabat, Daniel N., "Mutual information in Hawking radiation" (2013). CUNY Academic Works.