xbt, you were almost 100% right.  The report was made by CNN and was based on "two people briefed on the discussions."  The story's title is "Sources: White House lawyers research impeachment," but it says in the report that a White House official said "it's not true" and that an outside attorney close to the office of White House counsel Don McGahn cast doubt on impeachment preparations.  Unfortunately, most people reacting to the allegation do not know that because they never read more than a story's title.