While Sessions has recused himself directly from this case, he still runs Justice and has plenary supervising authority. How about if he issued a preservation order on ALL electronic devices used by all the investigators and staff, including private email accounts. The emails would be copied and turned over to a new investigative body, which would be singularly tasked to ascertain the indentity of the leaker(s) who are divulging privileged information. Guarantee full prosecution.
Are you talking about the investigation being run by Robert Muwller?